阅读说明：本技术 用于发射辐射到周围环境中的发送单元 (Transmitting unit for emitting radiation into the surroundings ) 是由 H-J·施瓦茨 S·施皮斯贝格尔 M·卡斯特纳 于 2018-05-09 设计创作，主要内容包括：本发明涉及一种用于发射辐射(209,209-1,209-2)到周围环境中的发送单元(100-1),具有·至少一个半导体激光器(102),其具有至少一个第一发射极,所述第一发射极具有第一部分(202)和第二部分(203),和·用于操控所述半导体激光器(102)的至少一个控制单元(101),其中,所述控制单元(101)构造为用于对所述至少一个发射极的第一部分(202)加载以第一供给变量(204)并且对所述至少一个发射极的第二部分(203)加载以与所述第一供给变量(204)不同的第二供给变量(205,301-1,301-2)。(The invention relates to a transmission unit (100-1) for emitting radiation (209,209-1,209-2) into the surroundings, having: -at least one semiconductor laser (102) having at least one first emitter having a first section (202) and a second section (203), and-at least one control unit (101) for actuating the semiconductor laser (102), wherein the control unit (101) is designed for applying a first supply variable (204) to the first section (202) of the at least one emitter and applying a second supply variable (205,301-1,301-2) different from the first supply variable (204) to the second section (203) of the at least one emitter.)

1. A transmitting unit (100-1) for emitting radiation (209,209-1,209-2) into an ambient environment, the transmitting unit having:

-at least one semiconductor laser (102) having at least one first emitter having a first portion (202) and a second portion (203), and

at least one control unit (101) for operating the semiconductor laser (102),

it is characterized in that the preparation method is characterized in that,

the control unit (101) is designed to load a first portion (202) of the at least one emitter with a first supply variable (204) and to load a second portion (203) of the at least one emitter with a second supply variable (205, 301-.

2. The transmitting unit (100-1) according to claim 1, characterized in that the first part (202) has a first region (502) with at least one semiconductor material and the second part (203) has a second region (503) with at least one semiconductor material, and the first region (502) and the second region (503) are spaced apart from each other.

3. The transmission unit (100-1) according to claim 2, characterized in that the semiconductor laser has at least two emitters (201-1,201-2), wherein,

each of the at least two emitters (201-.

4. The sending unit (100-1) according to claim 3, characterized in that the control unit (101) is configured for loading the respective second portion (203-.

5. The transmission cell (100-1) according to claim 4, characterized in that the time-dependent emission of the radiation (209-.

6. The transmitting unit (100-1) according to claim 4 or 5, characterized in that the transmitting unit (100-1) further has a detector (303) for detecting at least one reference radiation (302- "1,302-" 2), and in that the second supply variables (301- "1,301-" 2 ") assigned to the emitters (201-" 1,201- "2", respectively, are related to the at least one reference radiation (302- "1,302-" 2 ").

7. The transmission unit (100-1) according to any one of claims 1 to 6, characterized in that the transmission unit has a further optical element (103), in particular a deflection unit (207), for deflecting the radiation (209-1,209-2) emitted by the semiconductor laser into the surroundings along a deflection direction (208).

8. Lidar sensor (100) having a transmitting unit (100-1) according to any of claims 1 to 7, wherein the lidar sensor further has a receiving unit (100-2) for receiving radiation reflected by an object (104) in a surrounding environment.

9. Method for operating a transmitting unit (100-1) having at least one semiconductor laser (102) with at least one first emitter for emitting radiation (209-) 1,209-2 into the surroundings, the first emitter having a first section (202) and a second section (203), with the steps:

-loading the first part (202) with a first supply variable (204) by means of a control unit (101), and

-loading the second section (203) with a second supply variable (205, 301-.

10. The method of claim 9,

the semiconductor laser (102) has at least two emitters (201-

The respective second portion (203-.

11. Method according to claim 10, characterized in that it has the further step of:

detecting at least one reference radiation (302- < 1 >, 302-2) by means of a detector (303);

analyzing the at least one reference radiation (302-

The second supply variables (301-.

Technical Field

The invention relates to a transmitting unit for emitting radiation into the surroundings and to a method for operating a transmitting unit according to the preambles of the independent claims.

Background

The document PORTNOI, e.l., ultra high Power Picosecond Optical Pulses from Q-Switched Diode lasers, supra-Power Picosecond Optical Pulses from IEEE quantum electronics, journal of the theme of choice, 1997, 4, volume 3, No. 2, page 256, 260, discloses a semiconductor Laser operating with a passive Q-switch.

From US7428342, a lidar system is known in which a solid-state laser is operated by means of a passive Q-switch.

Disclosure of Invention

The invention proceeds from a transmission unit for emitting radiation into the surroundings, having at least one semiconductor laser, having at least one first emitter having a first section and a second section, and having at least one control unit for actuating the semiconductor laser.

According to the invention, the control unit is designed to apply a first supply variable to a first part of the at least one emitter and to apply a second supply variable, which is different from the first supply variable, to a second part of the at least one emitter.

The supply variable may be an electrical charge. The supply variable may be, for example, current or voltage. The first section may be referred to as an amplifier section. Charge carriers can be stored here, for example. The second portion may be referred to as a switching portion. The second part can be switched on and off rapidly. The radiation may be laser radiation. The laser radiation may be pulsed.

The first and second supply variables can differ from each other, for example, in their magnitude. The point in time at which the first portion is loaded with the first supply variable may be different from the point in time at which the second portion is loaded with the second supply variable. For this purpose, the contacting of the first part can be different from the contacting of the second part.

The advantage of the invention is that the semiconductor laser can be influenced in a targeted manner by means of the active Q-switch, i.e. with at least one second supply variable. The point in time at which the laser radiation is emitted can therefore be controlled very precisely by the semiconductor laser. The transmitting unit may emit (transmit) short laser pulses with high energy and high power. Compared with the use of, for example, solid-state lasers, high pulse repetition rates, in particular in the range from 100kHz to 1MHz, can be achieved with semiconductor lasers. Semiconductor lasers offer the advantages of smaller structure size and lower cost. Higher pulse powers can be achieved with the same pulse energy compared to a transmitting unit with a laser that cannot be switched by a Q-switch. This is advantageous in terms of eye safety of the transmitting unit and detection coverage of the receiving unit (improved signal-to-noise ratio).

In an advantageous embodiment of the invention, it is provided that the first part has a first region with at least one semiconductor material. The second portion has a second region having at least one semiconductor material. The first region and the second region are spaced apart from each other.

The first and second regions may be constructed of different materials. The first and second regions may be structured differently. A third region may be constructed between the first and second regions by spacing the first and second regions apart. The third region may be, for example, an insulating region, such that no charge can be transferred directly from the first region to the second region, or vice versa. Thus, the first and second regions can be electrically separated at least in the contact plane.

This has the advantage that contact-making of the first and second parts of the semiconductor laser can be realized on these semiconductor materials. By spacing the first and second regions apart, the loading of the first part with the first supply variable and the loading of the second part with the second supply variable can be defined and occur very precisely. Thus, for example, charge carrier exchange between the first and second regions can be avoided. This enables the amplifier section to be charged in a targeted manner. The second part can be switched in a targeted and fast manner.

In one embodiment of the invention, the semiconductor laser may have exactly one emitter. This has the advantage that the transmitting unit can emit laser radiation in the form of a punctiform laser beam with high energy and high power.

In a further advantageous embodiment of the invention, the semiconductor laser has at least two emitters. Each emitter of the at least two emitters has a first part assigned to the emitter in each case and a second part assigned to the emitter in each case.

This has the advantage that, when the at least two emitters are arranged next to one another, the transmitting unit can emit laser radiation in the form of a linear laser beam with high energy and high power. Other geometries of the laser beam are also conceivable, depending on the arrangement of the at least two emitters.

In a further advantageous embodiment of the invention, the control unit is designed for applying a second supply variable to the respective second part of each of the at least two emitters for assignment thereto, wherein the second supply variables are in particular different.

This has the advantage that each of the at least two emitters can be individually switched.

In a further advantageous embodiment of the invention, the time-dependent emission of the radiation can be generated by applying a respective second portion of each of the at least two emitters with a respective second supply variable assigned to the emitter.

This has the advantage that higher pulse powers and smaller pulse amplitudes can also be achieved.

In a further advantageous embodiment of the invention, the transmission unit also has a detector for detecting at least one reference radiation. The second supply variable associated with the emitter is dependent on the at least one reference radiation.

This has the advantage that the laser radiation emitted by each of the at least two emitters can be analyzed thereby. This allows the second supply variables assigned to the emitters in each case to be adapted. The adaptation can be carried out, for example, in such a way that the emission of the radiation can be better time-dependent.

In a further advantageous embodiment of the invention, the transmission unit has further optical elements. The transmitting unit has, in particular, a deflection unit for deflecting the radiation emitted by the semiconductor laser into the surroundings along a deflection direction. The deflection unit may be movable and its movement can be controlled. The deflection unit may be a mirror, for example.

This has the advantage that the radiation emitted by the semiconductor laser can be varied in its configuration and propagation direction. The propagation direction can thus be changed by means of an optical element, for example a mirror or a beam splitter. The configuration of the radiation can be changed, for example, by means of an optical lens or a prism. By actuating the movable deflection unit, the transmission unit can be used in systems in which the laser radiation must be able to be deflected in different spatial directions.

The invention also proceeds from a lidar sensor having a transmitting unit as has just been described. The lidar sensor further has a receiving unit for receiving radiation reflected by objects in the surrounding environment. The receiving unit may have a detector for detecting the received radiation. The detector may be, in particular, a Single Photon Avalanche photodiode detector (SPAD).

This has the advantage that an improved signal-to-noise ratio for the lidar sensor is obtained by the active Q-switch of the semiconductor laser. A good signal-to-noise ratio can be caused by short laser pulses of the transmitting unit with high energy and high power. The system resolution for the lidar sensor may be improved. The effective range of the lidar sensor described here can be significantly greater than in lidar sensors whose transmission unit does not have a semiconductor laser with an active Q-switch.

The invention further relates to a method for operating a transmission unit having at least one semiconductor laser having at least one first emitter for emitting radiation into the surroundings, the first emitter having a first section and a second section. The method comprises a step of loading the first part with a first supply variable by means of a control unit. The method also has the step of loading the second part with a second supply variable, which is different from the first supply variable, by means of a control unit.

In one advantageous embodiment of the invention, the semiconductor laser has at least two emitters. Each emitter of the at least two emitters has a first part assigned to the emitter in each case and a second part assigned to the emitter in each case. The respective second part of each of the at least two emitters is loaded with a second supply variable assigned to the emitter in each case. The second supply variable is in particular different.

In a further advantageous embodiment of the invention, the method has the further step of detecting at least one reference radiation by means of a detector. In a further step, the at least one reference radiation is analyzed. In a further step, the second supply variables respectively associated with the emitters are adapted on the basis of the analysis.

Drawings

Embodiments of the present invention are explained in detail below with reference to the drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. The figures show:

fig. 1a lidar sensor with a transmitting unit according to the invention;

fig. 2 a first embodiment of a transmitting unit;

fig. 3 a second embodiment of a transmitting unit;

FIG. 4A shows laser radiation emitted by a transmitting unit without time dependence;

FIG. 4B shows the laser radiation emitted by the transmitting unit with a time dependence;

fig. 5 a cross section of the emitter of a semiconductor laser.

Detailed Description

Fig. 1 schematically shows a schematic structure of a laser radar sensor 100. Lidar sensor 100 has a transmitting unit 100-1. The transmitting unit in turn has a control unit 101. The semiconductor laser 102 is controlled and operated by means of the control unit 101. The semiconductor laser 102 emits radiation in the form of laser radiation. The laser radiation may be pulsed. The laser radiation can be modified in its configuration and propagation direction by means of at least one further optical element 103 of the transmitting unit 100-1. The optical element 103 is only schematically shown here. The optical element 103 may be, for example, a mirror, a beam splitter, a lens, or a prism.

The laser radiation may be emitted (transmitted) into the surrounding environment. The laser radiation can be emitted (transmitted) into the surroundings after being modified by means of the optical element 103. In the surrounding environment, the laser radiation may be reflected by the object 104. In the surrounding environment, the laser radiation may be scattered by the object 104. Radiation reflected and/or scattered by object 104 may be received by receiving unit 100-2 of lidar sensor 100. The receiving unit 100-2 can also have an optical element 105 for this purpose. The received radiation may be directed onto the detector 106. Thereby generating a signal on the detector. The signal can be evaluated by means of the device 107 for signal processing.

Fig. 2 shows a transmission unit 100-1A as a first embodiment. The semiconductor laser 102 is shown having six emitters 201-1 through 201-6 (labeled 201-x below). For clarity, only emitters 201-1 and 201-2 and additional features assigned to these two emitters 201-1 and 201-2 are labeled. Each of the emitters 201-x of the semiconductor laser 102 has a first portion 202-x and a second portion 203-x. The first portion 202-x may be an amplifier portion. The second portion 203-x may be a switching portion. An example of a precise structure for such an emitter 201-x is illustrated in fig. 5 further below.

A first part 202-x of the six emitters 201-x shown is loaded with a first supply variable 204 by means of the control unit 101. Each of the first portions 202-x may be loaded with a first supply variable 204. For example, current 204 flows to amplifier portion 202-x. A second part 203-x of the six emitters 201-x shown is loaded with a second supply variable 205 by means of the control unit 101. Each of the second portions may be loaded with a second supply variable 205. For example, current 205 flows to switching section 203-x. The control unit 201 is preferably designed to carry out the loading of the first portion 202-x with the first supply variable 204 independently of the loading of the second portion 203-x with the second supply variable 205. For this purpose, the control unit 201 may be, for example, a multipart laser diode driver. Emitter 201-x can be switched on by actively loading second portion 203-x with second supply variable 205. Whereby the individual pulses of the six emitters 201-x may be time dependent. The individual pulses of emitter 201-x may be synchronized. High pulse energies and high pulse powers can thereby be achieved.

The positioning of the first portion 202-x and the second portion 203-x may vary. The first portion 202-x and the second portion 203-x may also be positioned such that the second portion 203-x is positioned closer to the control unit 201. This has the advantage of making the electrical connection of the control unit 201 to the switching section 203-x short. This results in a smaller inductance, which leads to a faster switching process at lower voltages. The switching section 203-x may also be mounted centrally with respect to the semiconductor laser 102. The switch portions 203-x can also be variably displaceably arranged. Each emitter 201-x may also be mounted with a plurality of switching sections 203-x-y (y-1 to z).

In the example shown, the pulsed laser beams of all emitters 201-x are concentrated by means of an optical lens 206 and focused onto a movable mirror 207. The laser radiation 209 is emitted in the form of a linear laser beam along the deflection direction 208 into the surroundings of the transmitting unit 100-1A.

Fig. 3 shows a transmitting unit 100-1B as a second embodiment. The same reference numerals as in fig. 1 or 2 designate the same or functionally same elements. Similar to the embodiment of fig. 2, the transmitting unit 100-1B may also have further optical elements, for example optical lenses or deflection mirrors. These further optical elements are not additionally shown in fig. 3.

The semiconductor laser 102 of the illustrated transmission unit 100-1B has six emitters 201-x. Each of said emitters 201-x has a first portion 202-x, i.e. an amplifier portion, and a second portion 203-x, i.e. a switching portion.

Furthermore, the transmitting unit 100-1B has a detector 303 for detecting the reference radiation 302-x from the rear facet of the emitter 201-x. The detector 303 may be, for example, a monitor-diode array. The reference radiation can be analyzed. The temporal sequence of laser pulses 209-x of emitter 201-x may be sensed in accordance with reference radiation 302-x. Signals 304 representing information about the time sequence may be transmitted to the control unit 101.

A first portion 202-x of the six emitters 201-x shown can be loaded with a first supply variable 204 by means of the control unit 101. Each of the first portions 202-x may be loaded with a first supply variable 204. The supply variable 204 can have the same magnitude for all six emitters 201-x. The amplifier portions 202-x of all emitters 201-x are charged by a common current 204.

A second part 203-x of the six emitters 201-x shown can be loaded by the control unit 101 with a second supply variable 205-x assigned to each emitter. For example, current 205-1 flowing to switching segment 203-1 may have a different magnitude than current 205-2 flowing to switching segment 203-2, and so on. In particular, the second supply variable 205-x can be adapted based on the information about the temporal sequence of the laser pulses 209-x of the emitter 201-x in such a way that the emission of the laser pulses 209-x is also more time-dependent. The synchronism of the emitted laser pulses 209-x is improved.

Fig. 4A shows a graph plotting the optical power 401 on the abscissa of the time 402. Qualitatively showing a single pulse 209-x of the emitter 201-x of a transmitting unit without time correlation/synchronization as shown for example in fig. 3.

Fig. 4B also shows a graph plotting the optical power 401 on the abscissa of time 402. Qualitatively showing a single pulse 209-x of the emitter 201-x of the transmitting unit 100-1 with time correlation/synchronization as shown for example in fig. 3. The synchronicity of the laser pulses 209-x is significantly improved compared to fig. 4A.

Alternatively, the detector 303 of the transmitting unit 100-1B may be a single monitor diode. The switching times of the individual emitters 201-x can be adapted for optimization by means of a computer program product with program code.

Furthermore, it is possible to individually control the emitters 201-x of the semiconductor lasers 102 of the transmission unit 100-1. For example, individual emitters 201-x may be purposefully turned off. This can be advantageous when strongly reflecting objects interfering with the measurement are located in the measurement path.

Fig. 5 shows a cross section of an emitter 201 of a semiconductor laser 102, which the transmitting unit 100-1 as shown in the preceding figures may have. Emitter 201 has a first portion 202 that can be loaded with a first supply variable 204. Emitter 201 also has a second portion 203 that can be loaded with a second supply variable 205. The emitter 201 may emit laser pulses 209.

The first portion 202 has a first region 502 having at least one semiconductor material. The second portion 203 has a second region 503 having at least one semiconductor material. The first region 502 and the second region 503 are spaced relative to each other. In the example, between the first region 502 and the second region 503 is an insulating region 501. The first region 502 and the second region 503 are arranged on a layer which the first portion 202 and the second portion may share. The first region 502 and the second region 503 may be disposed on a common waveguiding layer 504. An active region 505 may be disposed in the center of the waveguide layer 504. In addition, the first portion 202 and the second portion 203 may share a common base 506.