阅读说明：本技术 基于双波长的半导体激光器芯片封装 (Semiconductor laser chip package based on dual wavelength ) 是由 杨旭 刘哲 韩春霞 张岩松 于 2021-03-19 设计创作，主要内容包括：本发明提供一种基于双波长的半导体激光器芯片封装,应用于两个不同波长的激光芯片,包括：一个基板,一个被设于所述基板的顶面的第一正极打线区域,一个被设于所述基板的顶面的第一贴片区域,一个被设于所述基板的顶面的第二贴片区域和一个被设于所述基板的顶面的第二正极打线区域,一个被设于所述基板的底面的第一正极贴片焊盘,一个被设于所述基板的底面的第一负极贴片焊盘,一个被设于所述基板的底面的第二正极贴片焊盘和一个被设于所述基板的底面的第二负极贴片焊盘,和一个坝,所述坝被设于所述基板的外围。(The invention provides a semiconductor laser chip package based on dual wavelength, which is applied to two laser chips with different wavelengths, and comprises: the packaging structure comprises a substrate, a first positive wire bonding area arranged on the top surface of the substrate, a first patch area arranged on the top surface of the substrate, a second positive wire bonding area arranged on the top surface of the substrate, a first positive patch pad arranged on the bottom surface of the substrate, a first negative patch pad arranged on the bottom surface of the substrate, a second positive patch pad arranged on the bottom surface of the substrate, a second negative patch pad arranged on the bottom surface of the substrate, and a dam, wherein the dam is arranged on the periphery of the substrate.)

1. A semiconductor laser chip package based on dual wavelengths, comprising:

a substrate;

the laser chip comprises a substrate, a first anode routing area, a second anode routing area, a first chip area, a second chip area and a second chip area, wherein the first anode routing area is arranged on the top surface of the substrate, the first chip area is arranged on the top surface of the substrate, the second chip area is arranged on the top surface of the substrate, and the second anode routing area is arranged on the top surface of the substrate;

the first positive electrode patch bonding pad is arranged on the bottom surface of the substrate, the first negative electrode patch bonding pad is arranged on the bottom surface of the substrate, the second positive electrode patch bonding pad is arranged on the bottom surface of the substrate, and the second negative electrode patch bonding pad is arranged on the bottom surface of the substrate; and

a dam disposed around the substrate, the first positive routing area, the second routing area, the first patch area, and the second positive routing area being disposed within the dam.

2. The dual wavelength based semiconductor laser chip package of claim 1, wherein the wavelength range of the first laser chip is 800-1000nm and the wavelength range of the second laser chip is 400-700 nm.

3. The dual wavelength-based semiconductor laser chip package of claim 2, wherein the first laser chip is single-hole or array emitting, with a power of 1-300 milliwatts, and a far-field divergence angle of 18-23 °.

4. A dual wavelength based semiconductor laser chip package as claimed in claim 3 wherein the power of the second laser chip is in the range of 1-20 milliwatts and the far field divergence angle is in the range of 18-26 °.

5. The dual wavelength based semiconductor laser chip package of claim 4, wherein both said laser chips are P-side up and N-side down, and wherein the bottom of both said laser chips are attached to said first negative patch pad and said second negative patch pad by silver paste.

6. A dual wavelength based semiconductor laser chip package as claimed in claim 5, wherein the overall size of the package is 1.0 mmx0.5mm.

7. A dual wavelength based semiconductor laser chip package as claimed in claim 6 wherein a lens or a light homogenizer is added over said package.

8. A dual wavelength based semiconductor laser chip package as claimed in claim 7, wherein the primary material of the dam is ceramic or metal.

9. A dual wavelength based semiconductor laser chip package as claimed in claim 8 wherein said first and second patch regions are attached by conductive silver glue.

10. A dual wavelength based semiconductor laser chip package as claimed in claim 9 wherein the first anodic bonding area ranges from 0.55mm x 0.2mm, the first anodic bonding area being spaced from the dam by 0.1 mm.

11. A dual wavelength based semiconductor laser chip package as claimed in claim 10 wherein the first patch area is in the range of 0.55 x0.5mm and the first positive routing area and the first patch area are spaced 0.05mm apart.

12. A dual wavelength based semiconductor laser chip package as claimed in claim 11 wherein the second patch region ranges from 0.55 x0.5mm and the first patch region and the second patch region are spaced 0.15mm apart.

13. A dual wavelength based semiconductor laser chip package as claimed in claim 12 wherein the second anodic bonding area is in the range of 0.55mm x 0.2mm, the second anodic bonding area and the second patch area are spaced apart by 0.05mm, and the second anodic bonding area and the dam are spaced apart by 0.1 mm.

14. A dual wavelength based semiconductor laser chip package as claimed in claim 13 wherein the first and second laser chips range from 0.4mm x 0.45 mm.

15. A dual wavelength based semiconductor laser chip package as claimed in claim 14, wherein the internal area bounded by said dam is in the range of 0.65mm x 1.85mm and the overall area bounded by the outer edge of said dam is in the range of 0.8mm x 2 mm.

16. A method of fabricating a dual wavelength based semiconductor laser chip package comprising the steps of:

(A) preparing a substrate;

(B) forming a first anode routing area, a second anode routing area, a first patch area and a second patch area on the top surface of the substrate, wherein the first anode routing area, the first patch area, the second anode routing area and the second patch area are correspondingly and alternately generated on the top of the package, the first anode routing area and the first patch area are suitable for corresponding to a first laser chip, and the second patch area and the second anode routing area are suitable for corresponding to a second laser chip;

(C) forming a first positive patch pad, a second positive patch pad, a first negative patch pad and a second negative patch pad on the bottom surface of the substrate, wherein the first positive patch pad, the first negative patch pad, the second positive patch pad and the second negative patch pad are generated at the bottom of the package at intervals, the first positive patch pad and the first negative patch pad correspond to the first laser chip, and the second positive patch pad and the second negative patch pad correspond to the second laser chip; and

(D) preparing a dam at the periphery of the substrate, wherein the first anode routing area, the second anode routing area, the first patch area and the second patch area are enclosed in the dam.

Technical Field

The invention relates to an integrated scheme for packaging a semiconductor laser, in particular to a semiconductor laser chip package based on dual wavelengths.

Background

A VCSEL (vertical Cavity Emitting laser), which is an acronym of a vertical Cavity Surface Emitting laser, is based on a semiconductor laser diode, and is different from a conventional top and side Emitting LED and an edge Emitting laser, and the VCSEL can vertically emit a more efficient light beam from the Surface thereof.

The VCSEL has the outstanding advantages of low threshold value, small far-field divergence angle, high modulation frequency, easiness in realizing single longitudinal mode work, two-dimensional integration and the like, through development for many years, the VCSEL is widely applied to the fields of broadband Ethernet, high-speed data communication, optical interconnection, optical integrated elements and the like, and has wide market prospect and high commercial value.

The existing packaging of Vertical-Cavity Surface-Emitting Lasers (VCSELs) in the market is mainly a single semiconductor laser chip with single wavelength and a photoelectric detector, and the size of the existing packaging is mostly 3535 (3.5 mmx3.5mm) and 3532(3.5 mmx3.2mm). The main problem of the above products is highlighted by the fact that, firstly, the emission of a single wavelength limits the range for different probes or application scenarios; second, the existing larger package size package limits its application in devices due to the limited volume of the terminal device (such as watch, health bracelet) that is available.

The current market sensor adopts the scheme of LED packaging, the LED has far lower sensitivity than a laser due to wide spectrum, and the laser used for sensing mostly adopts a single-wavelength scheme, so that the range of detected substances is limited.

That is, the conventional vertical cavity surface emitting laser emits light with a single wavelength, and the application of the conventional vertical cavity surface emitting laser is limited by the limited sensing range of the single wavelength light emission, i.e., the application scene of the conventional vertical cavity surface emitting laser is limited.

That is to say, the actual size of the terminal device popular in the market, such as a watch and a health bracelet, is limited, and the terminal device has a smaller size, so that the internal assembly space that the terminal device can provide is more limited, and the size of the existing package of the existing vcsel in the market is larger than that of the terminal device, so that the two terminals cannot be adapted to each other, that is, the larger size of the existing package of the existing vcsel limits the type and range of the terminal product that can be used, and thus, the continuous development of further improving the share and commercial value of the vcsel in the market is hindered.

Disclosure of Invention

One advantage of the present invention is to provide a dual-wavelength-based semiconductor laser chip package, wherein the overall size of the package of the present invention is 1.0mmx0.5mm, which is advantageous for being adapted to a small-sized terminal device, thereby expanding the application range of the present invention, and contributing to improving market share and commercial value.

Another advantage of the present invention is to provide a dual wavelength based semiconductor laser chip package in which the chip size of the laser of the present invention is controlled.

Another advantage of the present invention is to provide a dual wavelength semiconductor laser chip package, wherein the overall photoelectric conversion efficiency of the present invention is 20% to 40%, the energy consumption is low, and the present invention is more environmentally friendly.

Another advantage of the present invention is to provide a dual wavelength based semiconductor laser chip package wherein the laser chip and package of the present invention have an extended useful life, typically up to 10 years or more.

Another advantage of the present invention is to provide a dual wavelength-based semiconductor laser chip package, wherein two semiconductor lasers with different wavelengths are introduced, the sensing range is expanded, the number of applications is increased, and the detection application scenario is expanded.

Another advantage of the present invention is to provide a dual-wavelength-based semiconductor laser chip package, wherein two semiconductor lasers with different wavelengths are introduced, and different wavelength bands can play a complementary role in applications such as gas smoke alarm (e.g., implementing detection of large particle dust), and blood oxygen sensing of wearable devices.

In order to achieve the above object, the present invention provides a semiconductor laser chip package based on dual wavelengths, comprising:

a substrate;

the laser chip comprises a substrate, a first anode routing area, a second anode routing area, a first chip area, a second chip area and a second chip area, wherein the first anode routing area is arranged on the top surface of the substrate, the first chip area is arranged on the top surface of the substrate, the second chip area is arranged on the top surface of the substrate, and the second anode routing area is arranged on the top surface of the substrate;

the first positive electrode patch bonding pad is arranged on the bottom surface of the substrate, the first negative electrode patch bonding pad is arranged on the bottom surface of the substrate, the second positive electrode patch bonding pad is arranged on the bottom surface of the substrate, and the second negative electrode patch bonding pad is arranged on the bottom surface of the substrate; and

a dam disposed around the substrate, the first positive routing area, the second routing area, the first patch area, and the second positive routing area being disposed within the dam.

According to an embodiment of the invention, the wavelength range of the first laser chip is 800-1000nm, and the wavelength range of the second laser chip is 400-700 nm.

According to one embodiment of the invention, the first laser chip emits light in a single hole or an array, the power is 1-300 milliwatts, and the far field divergence angle is 18-23 degrees.

According to one embodiment of the invention, the power of the second laser chip is 1-20 milliwatts, and the far field divergence angle is 18-26 degrees.

According to one embodiment of the invention, the two laser chips are both P-side up and N-side down, and the bottoms of the two laser chips are attached to the first negative patch bonding pad and the second negative patch bonding pad through silver paste.

According to one embodiment of the invention, the overall size of the package is 1.0 mmX0.5mm.

According to one embodiment of the invention, a lens or a light homogenizing sheet is added on top of the package.

According to one embodiment of the invention, the main material of the dam is ceramic or metal.

According to one embodiment of the invention, the first patch area and the second patch area are adhered by conductive silver adhesive.

According to one embodiment of the present invention, the first positive routing area is 0.55mm × 0.2mm, and the first positive routing area is spaced from the dam by 0.1 mm.

According to one embodiment of the invention, the first patch area is in the range of 0.55 × 0.5mm, and the interval between the first positive bonding area and the first patch area is 0.05 mm.

According to an embodiment of the invention, the second patch area is in the range of 0.55 x0.5mm, and the first patch area and the second patch area are spaced apart by 0.15 mm.

According to one embodiment of the invention, the range of the second positive routing area is 0.55mm × 0.2mm, the interval between the second positive routing area and the second patch area is 0.05mm, and the interval between the second positive routing area and the dam is 0.1 mm.

According to one embodiment of the invention, the range of the first laser chip and the second laser chip is 0.4mm × 0.45 mm.

According to one embodiment of the invention, the internal area of the dam is 0.65mm x 1.85mm and the overall area of the outer edge of the dam is 0.8mm x 2 mm.

In another aspect of the present invention, the present invention further provides a method for manufacturing a dual wavelength based semiconductor laser chip package, comprising the steps of:

(A) preparing a substrate;

(B) forming a first anode routing area, a second anode routing area, a first patch area and a second patch area on the top surface of the substrate, wherein the first anode routing area, the first patch area, the second anode routing area and the second patch area are correspondingly and alternately generated on the top of the package, the first anode routing area and the first patch area are suitable for corresponding to a first laser chip, and the second patch area and the second anode routing area are suitable for corresponding to a second laser chip;

(C) forming a first positive patch pad, a second positive patch pad, a first negative patch pad and a second negative patch pad on the bottom surface of the substrate, wherein the first positive patch pad, the first negative patch pad, the second positive patch pad and the second negative patch pad are generated at the bottom of the package at intervals, the first positive patch pad and the first negative patch pad correspond to the first laser chip, and the second positive patch pad and the second negative patch pad correspond to the second laser chip; and

(D) preparing a dam at the periphery of the substrate, wherein the first anode routing area, the second anode routing area, the first patch area and the second patch area are enclosed in the dam.

According to another aspect of the present invention, the present invention further provides a laser signal processing method, including the steps of:

(a) by energizing a first laser chip, said laser emitting a laser light which is reflected by a detected object, said laser light being received by a detector which converts an optical signal to obtain an electrical signal; and

(b) by energizing a second laser chip, the laser emits another laser, another laser is reflected by the detected object, another laser is received by another detector, and another detector converts the optical signal to obtain the electrical signal.

According to one embodiment of the invention, said step (a) further comprises the sub-steps of: when the first laser chip is powered on, the second laser chip is in a non-operating state.

According to one embodiment of the invention, said step (a) further comprises the sub-steps of: the laser light is reflected by the object to be detected.

According to an embodiment of the invention, said step (b) further comprises the sub-steps of: the wavelength of the second laser chip is different from the wavelength of the first laser chip.

According to an embodiment of the invention, said step (b) further comprises the sub-steps of: the wavelength of the other of said detectors is different from the wavelength of said detector of step (a).

Additional advantages and features of the invention will be set forth in the detailed description which follows and in part will be apparent from the description, or may be learned by practice of the invention as set forth hereinafter.

Further objects and advantages of the invention will be fully apparent from the ensuing description and drawings.

These and other objects, features and advantages of the present invention will become more fully apparent from the following detailed description, the accompanying drawings and the claims.

Drawings

Fig. 1 is a schematic top view of a dual wavelength based semiconductor laser chip package according to one embodiment of the present invention.

Fig. 2 is a bottom schematic view of a semiconductor laser chip package based on dual wavelengths according to the above-described embodiment of the present invention.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced devices or components must be in a particular orientation, constructed and operated in a particular orientation, and thus the above terms are not to be construed as limiting the present invention.

It is understood that the terms "a" and "an" should be interpreted as meaning that a number of one element or element is one in one embodiment, while a number of other elements is one in another embodiment, and the terms "a" and "an" should not be interpreted as limiting the number.

As shown in fig. 1, a schematic top view of a dual-wavelength-based semiconductor laser chip package according to an embodiment of the present invention is shown, wherein the dual-wavelength-based semiconductor laser chip package can be used for two laser chips, which are divided into a first laser chip and a second laser chip, the dual-wavelength-based semiconductor laser chip package includes a substrate 10, a first positive routing region 1 disposed on the top surface of the substrate 10, a second patch region 3 disposed on the top surface of the substrate 10, a first patch region 2 disposed on the top surface of the substrate 10, and a second positive routing region 4 disposed on the top surface of the substrate 10, wherein the first laser chip corresponds to the first positive routing region 1 and the first patch region 2, the second laser chip corresponds to the second patch region 3 and the second positive routing region 4, the first anode routing area 1 is distributed in an edge area of the top of the substrate 10, the first patch area 2 is adjacent to the first anode routing area 1 and is arranged at the top of the substrate 10, the second patch area 3 is adjacent to the first patch area 2 and is arranged at the top of the substrate 10, the second anode routing area 4 is adjacent to the second patch area 3 and is arranged at the top of the substrate 10, in other words, the second anode routing area 4 is arranged at the other edge area of the top of the substrate 10, and the first anode routing area 1, the first patch area 2, the second patch area 3 and the second anode routing area 4 are correspondingly, alternately and alternately arranged at the top of the substrate 10 and do not contact with each other.

Further, the first laser chip is bonded to the first anode routing area 1, the first laser chip is attached to the first chip area 2, the second laser chip is bonded to the second anode routing area 4, and the second laser chip is attached to the second chip area 3.

Furthermore, the thicknesses of the first anode routing area 1, the second patch area 3, the first patch area 2 and the second anode routing area 4 are equal, and after the first anode routing area, the second patch area, the first patch area and the second anode routing area are arranged on the top of the substrate 10, the heights of the bonding pads are consistent, and the situation of fluctuation cannot be caused.

Further, the black area shown in fig. 1 is a dam 9, the dam 9 forms a complete enclosure, and the dam 9 encloses the package. Further, the first anode routing area 1, the second patch area 3, the first patch area 2 and the second anode routing area 4 are disposed inside the dam 9, and the first anode routing area 1, the second patch area 3, the first patch area 2 and the second anode routing area 4 are enclosed by the dam 9.

Further, the main material of the dam 9 is ceramic or metal.

Furthermore, the first patch area 2 is adhered to the first laser chip through a conductive silver adhesive.

Furthermore, the second patch area 3 is adhered to the second laser chip through a conductive silver adhesive.

Further, the range of the first anode routing area 1 is 0.55mm × 0.2mm, and the interval between the first anode routing area 1 and the dam 9 is 0.1 mm.

Further, the range of the first chip area 2 is 0.55 × 0.5mm, and the interval between the first positive routing area 1 and the first chip area 2 is 0.05 mm.

Further, the second patch area 3 is in the range of 0.55 × 0.5mm, and the first patch area 2 and the second patch area 3 are spaced apart by 0.15 mm.

Further, the range of the second positive routing area 4 is 0.55mm × 0.2mm, the interval between the second positive routing area 4 and the second patch area 3 is 0.05mm, and the interval between the second positive routing area 4 and the dam 9 is 0.1 mm.

Further, the range of the first laser chip and the second laser chip is 0.4mm × 0.45 mm.

Further, the internal area range enclosed by the dam 9 is 0.65mm × 1.85mm, and the whole area range enclosed by the outer edge of the dam 9 is 0.8mm × 2 mm.

Referring to fig. 2, a schematic bottom view of a dual-wavelength-based semiconductor laser chip package according to the above embodiment of the present invention, wherein the dual-wavelength-based semiconductor laser chip package further includes a first positive patch pad 5 disposed on the bottom surface of the substrate 10, a first negative patch pad 6 disposed on the bottom surface of the substrate 10, a second positive patch pad 7 disposed on the bottom surface of the substrate 10, and a second negative patch pad 8 disposed on the bottom surface of the substrate 10, wherein the first laser chip corresponds to the first positive patch pad 5 and the first negative patch pad 6, and the second laser chip corresponds to the second positive patch pad 7 and the second negative patch pad 8, wherein the bottom of the package has four corner regions, wherein the first positive patch pad 5 is distributed on one corner region of the bottom of the package, the first negative electrode patch pad 6 is adjacent to the first positive electrode patch pad 5 and distributed in a corner area of the bottom of the package, the second positive electrode patch pad 7 is adjacent to the first positive electrode patch pad 5 and the second negative electrode patch pad 8 and distributed in a corner area of the bottom of the package, the second negative electrode patch pad 8 is adjacent to the first negative electrode patch pad 6 and the second positive electrode patch pad 7 and distributed in a corner area of the bottom of the package, wherein the first positive electrode patch pad 5, the first negative electrode patch pad 6, the second positive electrode patch pad 7 and the second negative electrode patch pad 8 are arranged at intervals in the bottom of the package and do not contact with each other.

Further, the thicknesses of the first positive electrode patch bonding pad 5, the first negative electrode patch bonding pad 6, the second positive electrode patch bonding pad 7 and the second negative electrode patch bonding pad 8 are equal, and after the positive electrode patch bonding pad, the heights of the bonding pads are consistent after the positive electrode patch bonding pad, the first negative electrode patch bonding pad and the second negative electrode patch bonding pad are arranged at the bottom of the package, and the situation of fluctuation cannot be caused.

Furthermore, the wavelength range of the first laser chip is 800-1000 nm.

Further, the wavelength range of the second laser chip is 400-700 nm.

Furthermore, the first laser chip is a single-hole light emitting or array light emitting, the light wavelength is 800-1000nm, the power is 1-300 milliwatts, and the far-field divergence angle is 18-23 degrees.

Furthermore, the optical wavelength of the second laser chip is 400-700nm, the power is 1-20 milliwatts, and the far field divergence angle is 18-26 degrees.

Furthermore, two laser chips are P face up, and N face down, and the bottom is pasted through the silver-colored glue in first negative pole paster pad with second negative pole paster pad.

Furthermore, the first positive electrode patch bonding pad and the second positive electrode patch bonding pad are respectively connected with the positive electrodes of the first laser chip and the second laser chip through gold wires.

Furthermore, a lens or a light homogenizing sheet can be added above the semiconductor laser chip package based on the dual wavelength according to an application scene to obtain a corresponding divergence angle.

Furthermore, the invention reduces the whole size of the package to 1.0mmX0.5mm by controlling the chip size of the laser under the condition of ensuring enough power, thereby being beneficial to reducing the size of the device and expanding the application range of the invention.

Furthermore, two semiconductor lasers with different wavelengths are introduced, and different wave bands can play complementary roles in gas smoke alarm (aiming at large particle dust) and blood oxygen sensing of wearable equipment.

Furthermore, the photoelectric conversion efficiency of the semiconductor laser chip package based on the dual wavelength is 20-40%, and the energy consumption is superior to that of the sensing scheme of the existing LED on the market by about 10%.

Furthermore, the laser chip and the package of the invention ensure the service life, and the service life can be more than 10 years under normal working conditions.

In the manufacturing scenario of the dual-wavelength-based semiconductor laser chip package, firstly, glue overflows to a certain extent around the first laser chip and the second laser chip during chip mounting, and the glue cannot overflow to the surfaces of the first laser chip and the second laser chip.

Further, the design for two chips, wherein the glue of the first laser chip must not overflow to the second laser chip. Once the glue overflows too much, the light of the chip can be blocked when reaching the surface of any laser chip, and further the optical power is reduced and the chip is in a bad point. Moreover, once the excessive glue overflow amount is too large, the glue of the two chips can be mixed together, and finally the electrodes are connected in series on the back surfaces of the two chips, so that the two chips are damaged.

Furthermore, the excessive glue overflowing amount is prevented by controlling the glue dripping amount in the process. That is, the dispensing amount is controlled by controlling the flow rate of one flow meter at each dispensing.

Furthermore, during the chip mounting, the glue overflowing amount is 1/2-1/3 of the whole glue amount of the conductive glue, and the lateral glue overflowing amount is 30-50 microns, so that the excessive glue overflowing amount is avoided, the waste of the glue is avoided, and the glue of the two chips is prevented from being fused together to influence the product performance.

Furthermore, the packaging process ensures the requirement of each laser chip on heat dissipation, and simultaneously realizes good conductivity, so that the photoelectric conversion efficiency of each laser chip is not influenced, and the packaged photoelectric characteristics are basically consistent with those of the bare chip.

Further, by electrifying each laser chip, the laser emits a laser, the laser is reflected by the detected object, the laser is received by a detector with corresponding wavelength, the detector converts an optical signal generated by the received laser into an electric signal, and the change of the optical signal is monitored, so that the purposes of detecting the change of the blood oxygen concentration, detecting the change of the air dust number and the like are achieved.

In the usage scenario of the dual-wavelength-based semiconductor laser chip package of the present invention, first, by powering on any one of the laser chips, the laser emits the laser, the laser is reflected by an object to be detected, the laser is received by the detector of one of the wavelengths, the detector converts the received optical signal into the electrical signal, and at this time, the other laser chip is in an inoperative state; the other laser chip is powered on, the laser emits the laser, the laser is reflected by a detected object, the laser is received by the detector with the other wavelength, the detector converts the received optical signal into the electric signal, and at the moment, any one laser chip is in a non-working state; when the laser light is received by the detectors of different wave bands, the other laser chip is in a non-working state. That is, the first laser chip is powered on, the laser emits the laser light, the laser light is reflected by the detected object, the laser light is received by the detector with another wavelength, and the detector converts the received optical signal into the electrical signal, and the second laser chip is in a non-operating state. In detail, the first laser chip and the second laser chip enable the laser to emit laser light with different wave bands, and the laser light with different wave bands can be received by the detectors with different wave bands respectively. Thus, by monitoring the optical signal and the change in the electrical signal, detection of changes in blood oxygen concentration, detection of changes in the amount of airborne dust, and others can be achieved.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are given by way of example only and are not limiting of the invention. The objects of the invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the examples, and any variations or modifications of the embodiments of the present invention may be made without departing from the principles.