阅读说明：本技术 一种减小剩余振幅调制的共振型电光调制器 (Resonance type electro-optical modulator capable of reducing residual amplitude modulation ) 是由 郑耀辉 焦南婧 李瑞鑫 田龙 王雅君 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种减小剩余振幅调制的共振型电光调制器,属于光学调制技术领域。本发明共振型电光调制器包括底座、绝缘垫片、温控铜炉、电路板底座、LC共振电路板、双层盖和电路板外壳,各个组件之间通过螺钉连接形成闭合空间,其中温控铜炉还包括温控铜炉外壳、TEC半导体制冷器、隔热片、温控铜炉盖、温控铜炉座、楔形晶体、走线隔热片、DC电极端温控铜炉外底座和AC电极端。本发明提供的一种减小剩余振幅调制的共振型电光调制器,提高电光调制装置的调制性能,减小相位调制中的剩余振幅调制,且减小外部温度变化对调制器性能的影响。(The invention discloses a resonance-type electro-optical modulator for reducing residual amplitude modulation, and belongs to the technical field of optical modulation. The resonance type electro-optic modulator comprises a base, an insulating gasket, a temperature control copper furnace, a circuit board base, an LC resonance circuit board, a double-layer cover and a circuit board shell, wherein all the components are connected through screws to form a closed space, the temperature control copper furnace further comprises the temperature control copper furnace shell, a TEC semiconductor refrigerator, a heat insulation sheet, a temperature control copper furnace cover, a temperature control copper furnace base, a wedge-shaped crystal, a routing heat insulation sheet, a DC electrode end temperature control copper furnace outer base and an AC electrode end. The invention provides a resonance type electro-optical modulator capable of reducing residual amplitude modulation, which improves the modulation performance of an electro-optical modulation device, reduces the residual amplitude modulation in phase modulation and reduces the influence of external temperature change on the performance of the modulator.)

1. A resonant-type electro-optic modulator that reduces residual amplitude modulation, characterized by: the device comprises a base (16), wherein an insulating gasket (15) is connected to the base (16) through a screw, and a temperature control copper furnace is arranged on the insulating gasket (15);

the temperature control copper furnace also comprises a temperature control copper furnace shell (5), a TEC semiconductor refrigerator (6), a heat insulating sheet (7), a temperature control copper furnace cover (8), a temperature control copper furnace base (9), a wedge-shaped crystal (10), a wiring heat insulating sheet (11), a DC electrode end (12), a temperature control copper furnace outer base (13) and an AC electrode end (14);

the temperature control copper furnace outer base (13) is connected with the temperature control copper furnace shell (5) wiring heat insulation sheet (11) through screws to form a closed cavity; the temperature control copper furnace outer base (13) is L-shaped and is connected to the insulating gasket (15) through a screw, and the lower bottom surface of the temperature control copper furnace outer base (13) is tightly attached to the upper top surface of the insulating gasket (15); the temperature control copper furnace shell (5) is Jiong-shaped, the centers of the side walls of the two sides of the temperature control copper furnace shell (5) are provided with light through holes (504), and the top wall of the temperature control copper furnace shell (5) is provided with a temperature control copper furnace shell thermistor through hole (502); two square grooves (131) are arranged on the temperature control copper furnace outer base (13),

a temperature control copper furnace base (9) is arranged in the closed cavity, a transverse groove is formed in the side face of the temperature control copper furnace base (9), a temperature control copper furnace base convex rib (903) is arranged in the middle of the transverse groove and used for adhering non-electrode faces of the wedge-shaped crystal (10) to enable the wedge-shaped crystal to be in precise contact with the non-electrode faces so as to improve the temperature control efficiency, the wedge-shaped crystal (10) corresponds to a light through hole (504) formed in the center of the side wall of the two sides of the temperature control copper furnace shell (5), a temperature control copper furnace base slotted hole (902) is further formed in the side face, provided with the transverse groove, of the temperature control copper furnace base (9) and used for containing a thermistor, and a heat insulation sheet (7) is movably arranged between the side face of the temperature control copper furnace base (9) and the side face of the temperature control copper furnace outer base (13) through screws so that the temperature; the electrode surfaces on the two sides of the wedge-shaped crystal (10) are respectively provided with an AC end electrode (14) and a DC end electrode (12);

the temperature control copper furnace cover (8) is movably arranged between the temperature control copper furnace base (9) and the wiring heat insulation sheet (11) through a screw, the contact surfaces are tightly attached, and a temperature control copper furnace cover through hole (802) is arranged on the surface of the temperature control copper furnace cover (8), corresponds to the temperature control copper furnace base slotted hole (902), and is used for passing through a thermistor;

the upper top surface and the lower bottom surface of the temperature control copper furnace base (9) are respectively provided with two TEC semiconductor refrigerators (6), and the two TEC semiconductor refrigerators (6) on the lower bottom surface of the temperature control copper furnace base (9) are fixed in two square grooves (131) arranged on the temperature control copper furnace outer base (13);

the circuit board base (3) is L-shaped and is movably arranged at the top of the temperature control copper furnace shell (5) through a screw, a DC end SMA interface (301) is arranged on the side wall of the circuit board base (3) and is used for connecting a joint for inputting a DC signal, an AC end SMA interface (302) is also arranged and is used for connecting a joint for inputting an AC signal, the joint for inputting the AC signal is connected with the LC resonance circuit board (2), and a temperature control end interface (303) is also arranged and is used for connecting a temperature control instrument; a circuit board base through hole (304) corresponding to the thermistor through hole (502) is formed in the bottom plate of the circuit board base (3) and is used for penetrating through the thermistor; the LC resonance circuit board (2) is movably arranged on a bottom plate of the circuit board base (3) through a screw; the circuit board shell (1) is Jiong-shaped, is buckled at the upper part of the circuit board base (3) and is fixed by a screw;

the double-layer cover (4) is arranged on the front side surfaces of the circuit board shell (1) and the temperature control copper furnace shell (5), so that the circuit board shell (1) and the temperature control copper furnace shell (5) form a closed space.

2. A resonant-type electro-optic modulator with reduced residual amplitude modulation as defined in claim 1, wherein: the end face of one side of the wedge-shaped crystal (10) is provided with an inclination angle of 4 degrees.

3. A resonant-type electro-optic modulator with reduced residual amplitude modulation as defined in claim 2, wherein: the AC end electrode (14) is slightly longer than the DC end electrode (12), the AC end electrode (14) is arranged at one end close to the inclined angle, and the two end electrodes are not in contact.

4. A resonant-type electro-optic modulator with reduced residual amplitude modulation as defined in claim 3, wherein: the bottom surface of base (16) is equipped with square groove (162) and is used for reducing area of contact.

5. A resonant-type electro-optic modulator with reduced residual amplitude modulation as defined in claim 4, wherein: the insulating gasket (15) is of a cuboid structure and is adhered to the temperature control copper furnace through glue.

Technical Field

The invention belongs to the technical field of optical modulation, and particularly relates to a resonance type electro-optical modulator capable of reducing residual amplitude modulation.

Background

The compressed state as a non-classical light has huge application potential in the field of quantum optics, and is an important quantum resource in the aspects of gravitational wave detection, precision measurement, quantum information field and the like. In the experimental preparation system of the compressed light field, the performance of a servo control system is a key technology for obtaining a high-compression quantum compressed state.

In the feedback control system based on the electro-optic phase modulation, because the electro-optic effect of the electro-optic crystal, namely when voltage is applied to the electro-optic crystal, the refractive index distribution of the electro-optic crystal in each direction can be changed, the phase of the light wave can be modulated by using an electro-optic phase modulator, the spectral line of the frequency discrimination signal is obtained by using the characteristics that the amplitudes of two modulation sidebands are equal and the phases are opposite, the optical cavity length and the relative phase are locked at the central zero-crossing point of the spectral line, and the stability of the optical cavity length and the relative phase is realized.

It is found from experiments that, after electro-optical phase Modulation, Residual Amplitude Modulation (RAM) occurs at the same time as the phase Modulation of the laser, which means that the positive and negative primary sidebands of the modulated light are not completely in equal-Amplitude anti-phase, and the asymmetry of the sidebands also changes with the change of the environment and experimental conditions. Causing the cavity length and the lock point of the phase to drift as the ambient temperature changes. The drift of the cavity length and the phase lock point is equivalent to phase noise, reducing the compressibility and long-term stability of the system.

As the experimental conditions improve and the experimental requirements further increase, the influence caused by the residual amplitude modulation is emphasized.

The existing commercial electro-optical modulator generally adopts a cuboid nonlinear crystal, which can generate a parasitic etalon effect, and can generate larger residual amplitude modulation due to the birefringence effect of the electro-optical crystal, uneven electric field distribution, radio frequency power jitter, laser frequency jitter and other reasons.

Disclosure of Invention

The present invention has been made in view of the above problems, and provides a resonance type electro-optical modulator that reduces residual amplitude modulation.

The invention aims to improve the modulation performance of an electro-optical modulation device, reduce residual amplitude modulation in phase modulation and reduce the influence of external temperature change on the performance of a modulator.

In order to achieve the purpose, the invention adopts the following technical scheme:

a resonance type electro-optic modulator for reducing residual amplitude modulation comprises a base, wherein an insulating gasket is connected to the base through a screw, and a temperature control copper furnace is arranged on the insulating gasket;

the temperature control copper furnace also comprises a temperature control copper furnace shell, a TEC semiconductor refrigerator, a heat insulation sheet, a temperature control copper furnace cover, a temperature control copper furnace base, a wedge-shaped crystal, a routing heat insulation sheet, a DC electrode end temperature control copper furnace outer base and an AC electrode end;

the temperature control copper furnace outer base is connected with the temperature control copper furnace outer shell wiring heat insulation sheet through screws to form a closed cavity; the temperature control copper furnace outer base is L-shaped and is connected to the insulating gasket through a screw, and the lower bottom surface of the temperature control copper furnace outer base is tightly attached to the upper top surface of the insulating gasket; the temperature control copper furnace shell is Jiong-shaped, light through holes are formed in the centers of the side walls of the two sides of the temperature control copper furnace shell, and a thermistor through hole of the temperature control copper furnace shell is formed in the top wall of the temperature control copper furnace shell; two square grooves are arranged on the temperature control copper furnace outer base,

a temperature control copper furnace base is arranged in the closed cavity, a transverse groove is formed in the side face of the temperature control copper furnace base, a temperature control copper furnace base convex edge is arranged in the middle of the transverse groove and used for pasting a non-electrode face of a wedge-shaped crystal, the wedge-shaped crystal is in precise contact with the non-electrode face to improve the temperature control efficiency, the wedge-shaped crystal corresponds to a light through hole formed in the center of the side wall of each of two sides of the temperature control copper furnace shell, a temperature control copper furnace base slotted hole is further formed in the side face of the temperature control copper furnace base with the transverse groove and used for containing a thermistor, and a heat insulation sheet is movably arranged between the temperature control copper furnace base and the side face of the temperature control copper furnace outer base through a screw to prevent the temperature control copper furnace from contacting with the temperature; the electrode surfaces on the two sides of the wedge-shaped crystal are respectively provided with an AC end electrode and a DC end electrode;

the temperature control copper furnace cover is movably arranged between the temperature control copper furnace base and the wiring heat insulation sheet through a screw, the contact surface is tightly attached, and the temperature control copper furnace cover through hole is arranged on the surface of the temperature control copper furnace cover and corresponds to the temperature control copper furnace base slot hole for passing through the thermistor;

the upper top surface and the lower bottom surface of the temperature control copper furnace base are respectively provided with two TEC semiconductor refrigerators, and the two TEC semiconductor refrigerators on the lower bottom surface of the temperature control copper furnace base are fixed in two square grooves arranged on the temperature control copper furnace outer base;

the circuit board base is L-shaped and movably arranged at the top of the temperature control copper furnace shell through a screw, a DC end SMA interface is arranged on the side wall of the circuit board base and is used for connecting a joint for inputting a DC signal, an AC end SMA interface is also arranged and is used for connecting a joint for inputting an AC signal, wherein the joint for inputting the AC signal is connected with the LC resonance circuit board, and a temperature control end interface is also arranged and is used for connecting a temperature controller; a circuit board base through hole corresponding to the thermistor through hole is formed in the bottom plate of the circuit board base and is used for penetrating through the thermistor; the LC resonance circuit board is movably arranged on a bottom plate of the circuit board base through a screw; the circuit board shell is Jiong-shaped, is buckled at the upper part of the circuit board base and is fixed by a screw;

the double-layer cover is arranged on the front side surfaces of the circuit board shell and the temperature control copper furnace shell, so that a closed space is formed by the circuit board shell and the temperature control copper furnace shell.

Further, the end face on one side of the wedge-shaped crystal is provided with an inclination angle of 4 degrees.

Further, the AC end electrode is slightly longer than the DC end electrode, the AC end electrode is arranged at one end close to the inclined angle, and the two end electrodes are not in contact.

Furthermore, the bottom surface of the base is provided with a square groove for reducing the contact area.

Furthermore, the insulating gasket is of a cuboid structure and is adhered to the temperature control copper furnace through glue.

The temperature control design part firstly wraps the crystal by using an insulating and heat-conducting material, then wraps the designed heat-insulating copper furnace on the periphery of the material to wrap the material wrapped with the crystal, inserts a thermistor on the heat-insulating copper furnace in the middle of the crystal block, monitors the change of the temperature of the crystal by using a temperature controller, and completely pastes the upper and lower cross sections of the heat-insulating copper furnace with a semiconductor cooler (TEC) for feeding back temperature control.

Compared with the prior art, the invention has the following advantages:

the invention provides an integrated electro-optical modulation device, which loads alternating current and direct current voltages in different areas of the same crystal respectively. When the crystal is applied with alternating current and direct current voltages in the same electrode area, a high-voltage-resistant capacitor needs to be added at a direct current end under the condition, and the method is feasible if the alternating current or direct current voltage is directly and simply applied to the crystal; however, the device of the application uses the LC resonance circuit and achieves the purpose of reducing the voltage amplitude of direct output by amplifying the voltage at the resonance frequency; the LC resonance circuit and the direct current end are loaded to the crystal through the high-voltage-resistant capacitor to form a loop, so that new LC resonance is formed, the original resonance frequency point is deviated, and alternating current loading is distorted. The scheme of loading alternating current and direct current voltages in different areas of the same crystal is more feasible, the scheme of loading the alternating current and direct current voltages on the crystal independently and putting the crystal into a light path is mainly used for phase modulation, the scheme of loading the alternating current and direct current voltages on the crystal independently is used for amplitude modulation, but residual amplitude modulation is inevitably introduced; therefore, after the phase modulation is carried out by loading alternating voltage on different areas on one crystal, the residual amplitude modulation is compensated by loading proper amplitude modulation on the other area to generate a negative feedback effect, and the aim of reducing the residual amplitude modulation is fulfilled.

The inclination angle of 4 degrees is cut at one end of the crystal, when the polarization direction of incident linearly polarized light and the optical axis of the electro-optic crystal are not coincident, due to the birefringence effect of the crystal, the cut angle of the rear end face can separate the light in two polarization directions which are perpendicular to each other in space, so that the interference between a carrier and two sidebands which are perpendicular to each other can be eliminated, and the influence of residual amplitude modulation caused by the deviation of the polarization direction of incident linearly polarized light in the phase modulation process is weakened. In addition, the wedge crystal can also eliminate the etalon effect.

The integrated electro-optical modulation device can reduce the residual amplitude modulation, improve the performance of a feedback control system and is beneficial to obtaining a compressed state light field with high compression degree and stable operation.

Drawings

FIG. 1 is an exploded view of a resonant electro-optic modulator according to the present invention;

FIG. 2 is a schematic diagram of the structure of the circuit board housing of the present invention;

FIG. 3 is a schematic structural diagram of a circuit board base according to the present invention;

FIG. 4 is a schematic structural view of a double-layer lid according to the present invention;

FIG. 5 is a schematic structural view of the temperature controlled copper furnace enclosure of the present invention;

FIG. 6 is a schematic structural view of a temperature-controlled copper furnace lid according to the present invention;

FIG. 7 is a schematic structural view of a temperature-controlled copper furnace base according to the present invention;

FIG. 8 is a schematic view of the structure of the base and wedge-shaped crystal of the temperature controlled copper furnace of the present invention;

FIG. 9 is a schematic diagram showing the positions of the base and the wedge crystal of the temperature controlled copper furnace according to the present invention;

fig. 10 is a schematic structural view of a trace insulation sheet according to the present invention;

FIG. 11 is a schematic structural view of the outer base of the temperature-controlled copper furnace of the present invention;

FIG. 12 is a schematic rear view of the temperature-controlled copper furnace outer base according to the present invention

FIG. 13 is a schematic view of the structure of the insulating spacer of the present invention;

FIG. 14 is a schematic structural view of a base according to the present invention;

FIG. 15 is a schematic top view of the base of the present invention;

FIG. 16 is a front view of the present invention;

FIG. 17 is a test state diagram of the present invention;

FIG. 18 is a schematic diagram of the structures of a wedge-shaped crystal, AC terminal electrodes, DC terminal electrodes, and tilt angles according to the present invention.

Wherein, 1-circuit board shell, 101-circuit board shell top M2 cross socket head screw taper hole, 102-circuit board shell bottom M2 cross socket head screw taper hole, 2-LC resonance circuit board, 3-circuit board base, 301-DC end SMA interface, 302-AC end SMA interface, 303-temperature control end interface, 304-through hole, 305-inner ring M2 bottom screw hole, 306-outer ring M2 bottom screw hole, 307-M2 side bottom screw hole, 4-double cover, 401-double cover top M2 screw hole, 402-double cover side M2 bottom screw hole, 5-temperature control copper furnace shell, 501-temperature control copper furnace shell through hole, 502-temperature control copper furnace shell thermistor through hole, 503-temperature control copper furnace shell M2 top screw hole, 504-through light hole, 505-temperature control copper furnace shell bottom center M2 cross socket head screw taper hole, 506-temperature control copper furnace shell bottom M2 cross head taper hole, 6-TEC (semiconductor cooler), 7-heat-insulating sheet, 8-temperature control copper furnace cover, 801-temperature control copper furnace cover M2 cross concave head screw taper hole, 802-temperature control copper furnace cover through hole, 9-temperature control copper furnace base, 901-temperature control copper furnace base M2 bottom screw hole, 902-temperature control copper furnace base circular slot hole, 903-temperature control copper furnace base convex edge, 10-wedge crystal, 11-routing heat-insulating sheet, 111-electrode wiring hole, 112-routing heat-insulating sheet upper M2 cross concave head screw taper hole, 113-routing heat-insulating sheet lower M2 cross concave head screw taper hole, 114-TCE wiring slot, 12-DC end electrode, 13-temperature control copper furnace outer base, 131-temperature control copper furnace outer base, 132-temperature control copper furnace outer base front M2 bottom screw hole, 133-temperature control copper furnace outer base side M2 bottom screw hole, 134-temperature control copper furnace outer base bottom M2 bottom screw hole, 14-AC electrode, 15-AC insulation gasket 151-2 insulation gasket, 152-a threaded hole at the bottom of the insulating gasket M4, 16-a base, 161-a countersunk hole at the base M4 and 162-a square groove at the base.

Detailed Description

Example 1

A resonance type electro-optic modulator for reducing residual amplitude modulation comprises a base 16, wherein an insulating gasket 15 is connected to the base 16 through a screw, and a temperature control copper furnace is arranged on the insulating gasket 15;

the temperature control copper furnace also comprises a temperature control copper furnace shell 5, a TEC semiconductor refrigerator 6, a heat insulating sheet 7, a temperature control copper furnace cover 8, a temperature control copper furnace base 9, a wedge-shaped crystal 10, a routing heat insulating sheet 11, a DC electrode end 12, a temperature control copper furnace outer base 13 and an AC electrode end 14;

the temperature control copper furnace outer base 13 is connected with the wiring heat insulation sheet 11 of the temperature control copper furnace shell 5 through screws to form a closed cavity; the temperature control copper furnace outer base 13 is L-shaped and is connected to the insulating gasket 15 through a screw, and the lower bottom surface of the temperature control copper furnace outer base 13 is tightly attached to the upper top surface of the insulating gasket 15; the temperature control copper furnace shell 5 is Jiong-shaped, the centers of the side walls of the two sides of the temperature control copper furnace shell 5 are provided with light through holes 504, and the top wall of the temperature control copper furnace shell 5 is provided with a temperature control copper furnace shell thermistor through hole 502; two square grooves 131 are arranged on the temperature control copper furnace outer base 13,

a temperature control copper furnace base 9 is arranged in the closed cavity, a transverse groove is formed in the side face of the temperature control copper furnace base 9, a temperature control copper furnace base convex edge 903 is arranged in the middle of the transverse groove and used for adhering a non-electrode face of the wedge-shaped crystal 10, the wedge-shaped crystal 10 is in precise contact with the non-electrode face so as to improve the temperature control efficiency, the wedge-shaped crystal 10 corresponds to a light through hole 504 formed in the center of the side wall of the two sides of the temperature control copper furnace shell 5, a temperature control copper furnace base circular groove hole 902 is further formed in the side face of the temperature control copper furnace base 9, which is provided with the transverse groove and used for accommodating a thermistor, and a heat insulation sheet 7 is movably arranged between the temperature control copper furnace base 9 and the side face of the temperature control copper furnace outer base 13 through screws, so that the temperature; the electrode surfaces on the two sides of the wedge-shaped crystal 10 are respectively provided with an AC end electrode 14 and a DC end electrode 12;

the temperature control copper furnace cover 8 is movably arranged between the temperature control copper furnace base 9 and the wiring heat insulation sheet 11 through a screw, the contact surfaces are tightly attached, and a temperature control copper furnace cover through hole 802 is arranged on the surface of the temperature control copper furnace cover 8 and corresponds to the temperature control copper furnace base circular groove hole 902 and is used for passing through a thermistor;

the upper top surface and the lower bottom surface of the temperature control copper furnace base 9 are respectively provided with two TEC semiconductor refrigerators 6, and the two TEC semiconductor refrigerators 6 on the lower bottom surface of the temperature control copper furnace base 9 are fixed in two square grooves 131 arranged on the temperature control copper furnace outer base 13;

the circuit board base 3 is L-shaped and is movably arranged at the top of the temperature control copper furnace shell 5 through a screw, a DC end SMA interface 301 for connecting a joint for inputting a DC signal is arranged on the side wall of the circuit board base 3, an AC end SMA interface 302 for connecting a joint for inputting an AC signal is also arranged, the joint for inputting the AC signal is connected with the LC resonance circuit board 2, and a temperature control end interface 303 for connecting a temperature controller is also arranged; a circuit board base through hole 304 corresponding to the temperature control copper furnace shell thermistor through hole 502 is formed in the bottom plate of the circuit board base 3 and is used for penetrating through a thermistor; the LC resonance circuit board 2 is movably arranged on a bottom plate of the circuit board base 3 through a screw; the circuit board shell 1 is in Jiong shape, is buckled at the upper part of the circuit board base 3 and is fixed by a screw;

the double-layer cover 4 is arranged on the front side surfaces of the circuit board shell 1 and the temperature control copper furnace shell 5, so that the circuit board shell 1 and the temperature control copper furnace shell 5 form a closed space.

Further, the end face on the side of the wedge crystal 10 is provided with an inclination angle of 4 degrees.

Further, the AC terminal electrode 14 is slightly longer than the DC terminal electrode 12, the AC terminal electrode 14 is disposed near one end where the inclination angle is set, and the two terminal electrodes are not in contact.

Further, the bottom surface of the base 16 is provided with a base square groove 162 for reducing the contact area.

Further, the insulating gasket 15 is of a cuboid structure and is adhered to the temperature control copper furnace through glue.

Example 2

As shown in the exploded structural diagram of the resonant electro-optic modulator of fig. 1, a resonant electro-optic modulator with reduced residual amplitude modulation:

as shown in the schematic structural diagrams of the insulating spacer and the base in fig. 13, 14 and 15, two countersunk holes M4 161 are formed in the base 16, two threaded holes 152 at the bottom of the insulating spacer M4 are formed in the insulating spacer 15, and screws pass through the two countersunk holes 161M 4 and the threaded holes 152 at the bottom of the insulating spacer M4 to fixedly connect the base 16 and the insulating spacer 15;

as shown in fig. 12 and 13, the structural schematic diagrams of the temperature-controlled copper furnace outer base and the insulating spacer are shown, wherein 4 insulating spacer M2 countersunk holes 151 are formed in the insulating spacer 15, 4 temperature-controlled copper furnace outer base bottom surfaces M2 threaded holes 134 are formed in the lower bottom surface of the temperature-controlled copper furnace outer base 13, and screws penetrate through the 4 insulating spacer M2 countersunk holes 151 and the 4 temperature-controlled copper furnace outer base bottom surfaces M2 threaded holes 134 to fixedly connect the temperature-controlled copper furnace outer base 13 and the insulating spacer 15;

as shown in the structural schematic diagrams of the temperature-controlled copper furnace base and the wedge-shaped crystal in fig. 5, 6, 7, 8 and 9, a transverse groove is formed in the side surface of the temperature-controlled copper furnace base 9, and a temperature-controlled copper furnace base rib 903 is arranged in the middle of the transverse groove; 4 temperature control copper furnace seats M2 bottom threaded holes 901 are arranged on the side surface of the temperature control copper furnace seat 9 provided with a transverse groove, and 4 temperature control copper furnace covers M2 cross socket head screw conical holes 801 are arranged on the temperature control copper furnace cover 8; a temperature control copper furnace base circular groove hole 902 is also arranged on the side surface of the temperature control copper furnace base 9 with the transverse groove and used for installing a thermistor;

as shown in fig. 18, the end face on one side of the wedge crystal 10 is provided with an inclination of 4 degrees; the electrode surfaces on the two sides of the wedge-shaped crystal 10 are respectively provided with an AC end electrode 14 and a DC end electrode 12; the AC end electrode 14 is slightly longer than the DC end electrode 12, the AC end electrode 14 is arranged on the electrode surface close to one end with an inclination angle, the two end electrodes are not contacted, the wedge-shaped crystal 10 is arranged in the temperature control copper furnace seat convex rib 903, the non-electrode surface of the wedge-shaped crystal 10 is pasted, and the wedge-shaped crystal 10 is precisely contacted with the temperature control copper furnace seat 9 to improve the temperature control efficiency; the temperature control copper furnace cover through hole 802 is arranged on the surface of the temperature control copper furnace cover 8 and corresponds to the temperature control copper furnace base circular groove hole 902 for passing through the thermistor;

screws penetrate through 4 conical holes 801 of the cross-shaped socket head screws of the temperature control copper furnace cover M2 and threaded holes 901 at the bottom of 4 temperature control copper furnace seats M2 to fixedly connect the temperature control copper furnace cover 8 with the temperature control copper furnace seats 9; the upper top surface and the lower bottom surface of the temperature control copper furnace base 9 are respectively provided with two TEC semiconductor refrigerators 6, and the two TEC semiconductor refrigerators 6 on the lower bottom surface of the temperature control copper furnace base 9 are fixed in two square grooves 131 arranged on the temperature control copper furnace outer base 13;

as shown in fig. 10, a temperature-controlled copper furnace outer base front M2 bottom threaded hole 132 is provided on the front end face of the temperature-controlled copper furnace outer base 13, a wiring heat insulating sheet lower part M2 cross concave screw conical hole 113 is provided on the wiring heat insulating sheet 11 at a position corresponding to the temperature-controlled copper furnace outer base front M2 bottom threaded hole 132, a screw passes through the temperature-controlled copper furnace outer base front M2 bottom threaded hole 132 and the wiring heat insulating sheet lower part M2 cross concave screw conical hole 113 to fixedly link the wiring heat insulating sheet 11 with the temperature-controlled copper furnace outer base 13; two routing heat insulation sheets upper M2 cross socket head screw taper holes 112 are arranged on the routing heat insulation sheet 11;

the heat insulation sheet 7 is movably arranged between the temperature control copper furnace seat 9 and the side surface of the temperature control copper furnace outer base 13 through screws, so that the temperature control copper furnace is not contacted with the temperature control copper furnace shell 5 to prevent heat conduction;

the temperature control copper furnace shell 5 is Jiong-shaped, the centers of the side walls of the two sides of the temperature control copper furnace shell 5 are provided with light through holes 504, and the top wall of the temperature control copper furnace shell 5 is provided with a temperature control copper furnace shell thermistor through hole 502; two threaded holes 503 at the top of the temperature-controlled copper furnace shell M2 are correspondingly arranged at the side part of the top wall of the temperature-controlled copper furnace shell 5 and the two threaded holes 112 at the top M2 of the routing heat-insulating sheet 11, and the screws penetrate through the threaded holes 112 at the top M2 of the two threaded holes and the two threaded holes 503 at the top M2 of the two threaded heat-insulating sheet top to fix the routing heat-insulating sheet 11 on the temperature-controlled copper furnace shell 5;

the bottom of the side walls at two sides of the temperature control copper furnace outer shell 5 is provided with a temperature control copper furnace outer shell bottom center M2 cross concave head screw conical hole 505, two sides of the bottom of the temperature control copper furnace outer base 13 are provided with two M2 bottom threaded holes, and the screw penetrates through the temperature control copper furnace outer shell bottom center M2 cross concave head screw conical hole 505 and the two M2 bottom threaded holes to fix the temperature control copper furnace outer shell on the temperature control copper furnace outer base 13;

4 temperature control copper furnace shell through holes 501 are formed in the top of the temperature control copper furnace shell 5, 4 corresponding outer ring M2 bottom threaded holes 306 are formed in the bottom of the circuit board base 3, and screws penetrate through the 4 temperature control copper furnace shell through holes 501 and the 4 outer ring M2 bottom threaded holes 306 to fix the circuit board base 3 on the temperature control copper furnace shell 5;

as shown in fig. 2, 3 and 4, a DC-end SMA interface 301 for connecting a connector for inputting a DC signal and an AC-end SMA interface 302 for connecting a connector for inputting an AC signal are provided on the side wall of the circuit board base 3, wherein the connector for inputting an AC signal is connected to the LC resonance circuit board 2, and a temperature-control-end interface 303 for connecting a temperature controller is provided;

a circuit board base through hole 304 corresponding to the temperature control copper furnace shell thermistor through hole 502 is formed in the bottom plate of the circuit board base 3 and is used for penetrating through a thermistor; the LC resonance circuit board 2 is movably arranged on a bottom plate of the circuit board base 3 through a screw; the circuit board shell 1 is shaped like Jiong and is buckled on the upper part of the circuit board base 3,

two M2 side bottom threaded holes 307 are arranged on two sides of the bottom plate of the circuit board base 3, two M2 cross socket head screw conical holes 102 are arranged on the bottom of the side wall of the two sides of the circuit board shell 1, and screws penetrate through the two M2 side bottom threaded holes 307 and the two M2 cross socket head screw conical holes 102 to fix the circuit board shell 1 on the circuit board base 3

The upper end face of the double-layer cover 4 is provided with two double-layer cover top M2 threaded holes 401, the top of the circuit board shell 1 is provided with two circuit board shell top M2 cross concave head screw conical holes 101, the bottom of the side wall at two sides of the temperature control copper furnace shell 5 is provided with two temperature control copper furnace shell bottom M2 cross concave head screw conical holes 506, and the bottom of the two side end faces of the double-layer cover 4 is provided with two double-layer cover side M2 bottom threaded holes 402;

the double-layer cover is arranged on the front side faces of the circuit board shell 1 and the temperature control copper furnace shell 5, screws penetrate through two double-layer cover top M2 threaded holes 401 and two circuit board shell top M2 cross concave head screw conical holes 101 to fix the double-layer cover 4 on the circuit board shell 1, the screws penetrate through two temperature control copper furnace shell bottom side M2 cross concave head screw conical holes 506 and two double-layer cover side M2 bottom threaded holes 402 to fix the double-layer cover 4 on the temperature control copper furnace shell 5, and the circuit board shell 1 and the temperature control copper furnace shell 5 form a closed space.

After the assembly is completed, the overall structure is schematically shown in fig. 16.

Example 3

A method of testing a resonant-type electro-optic modulator with reduced residual amplitude modulation, comprising the steps of:

step 1, sticking the wedge-shaped crystal in a heat-preservation copper furnace, and respectively welding an AC end electrode wire, a DC end electrode wire and a TEC and thermistor wire of the wedge-shaped crystal to respective coupling heads;

step 2, assembling the resonance type electro-optic modulator, starting an all-solid-state single-frequency Nd, namely a 1064nm laser of a YVO4 laser, stably outputting 1064nm light by using the laser and collimating a light beam;

step 3, an optical isolator (OI1) placed after the collimated light beam is used to minimize back reflection.

Step 4, placing and using a Glan-Thompson prism (GTP) after the step, and ensuring that the purity of the linearly polarized light beam incident to the EOM is better than 1: 100000.

Step 5, placing an electro-optical amplitude modulator behind the wedge-shaped crystal, and enabling light to enter the electro-optical amplitude modulator along the center of the wedge-shaped crystal, wherein a coupling head of the electro-optical amplitude modulator is connected with a temperature controller and a signal generator respectively; the temperature controller is used for controlling the temperature of the crystal, and the signal generator adds a modulation signal to the electro-optical amplitude modulator;

another GTP is positioned after the EOM, as a downstream polarizing optical element, aligned along the direction of propagation of the extraordinary wave, step 6.

Step 7, a beam splitter is placed in front of the OPO cavity, where its reflected beam is directly coupled to a photodetector (PD 1). The output of the beam splitter is fed to a radio frequency spectrum analyzer to measure the noise power spectrum of the phase modulated light.

Step 8, an optical isolator (OI2) in front of the cavity is used to extract the cavity's reflected signal, and an additional optical isolator (OI3) is placed in front of the photodetector to suppress the parasitic etalon effect in the optical setup. The photodetector (PD2) reads the OPO reflected signal from the opto-isolator (OI 2). The phase of the local signal is adjusted to give a maximum error signal in the mixer output.

And 9, when the laser frequency is tuned to be far away from the resonant cavity resonance, outputting a zero base line corresponding to the error signal by the mixer, feeding the zero base line to an NI Data Acquisition Card (DAC) to measure the zero drift of the PDH error signal, and effectively reducing the peak value of the ZBD drift of the zero base line of the PDH error signal, namely completing the test.

Those skilled in the art will appreciate that the invention may be practiced without these specific details. Although illustrative embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the embodiments, and various changes may be made apparent to those skilled in the art as long as they are within the spirit and scope of the present invention as defined and defined by the appended claims, and all matters of the invention which utilize the inventive concepts are protected.