CN115668671A

CN115668671A - Multichannel semiconductor laser, laser radar system and vehicle

Info

Publication number: CN115668671A
Application number: CN202280003607.8A
Authority: CN
Inventors: 胡小波; 史鹏飞; 梁志发
Original assignee: LeiShen Intelligent System Co Ltd
Current assignee: LeiShen Intelligent System Co Ltd
Priority date: 2022-09-07
Filing date: 2022-09-07
Publication date: 2023-01-31
Also published as: WO2024050717A1

Abstract

The application discloses multichannel semiconductor laser, laser radar system and vehicle. The multichannel semiconductor laser comprises a circuit board and at least two laser emitting units, wherein the circuit board is set to control laser chips corresponding to the at least two laser emitting units to emit laser beams, the laser chips comprise a first laser chip used for emitting laser beams of frequency modulation continuous wave type and a second laser chip used for emitting laser beams of pulse type, and the line width of the laser beams of the frequency modulation continuous wave type is smaller than the line width of the laser beams of the pulse type.

Description

Multichannel semiconductor laser, laser radar system and vehicle

Technical Field

The present application relates to the field of optical device technology, for example to a multi-channel semiconductor laser, a lidar system and a vehicle.

Background

A LiDAR (LiDAR) is a device that measures a distance or a speed of a target by irradiating the target with laser light, and can be used to detect and avoid obstacles in a vehicle, thereby improving the safety of the vehicle in traveling.

In the related art, two different types of laser radars, namely a Time of Flight (TOF) laser radar and a Frequency Modulated Continuous Wave (FMCW) laser radar, are mounted in a vehicle, so that the detection performance of a laser radar sensor is improved. However, the laser chip of the semiconductor laser in the related art is single in type, and one semiconductor laser cannot meet different light source requirements of the TOF laser radar and the FMCW laser radar at the same time.

Disclosure of Invention

The application provides a multichannel semiconductor laser, laser radar system and vehicle can overcome the shortcoming that semiconductor laser's laser chip kind is single among the correlation technique, satisfies TOF laser radar and FMCW laser radar's different light source demands.

According to an aspect of the present application, there is provided a multi-channel semiconductor laser including a circuit board and at least two laser emitting units;

the circuit board is electrically connected with the at least two laser emitting units, and the circuit board is arranged to control the laser chips corresponding to the at least two laser emitting units to emit laser beams;

the laser chip comprises a first laser chip and a second laser chip, the first laser chip is set to emit laser beams of frequency modulation continuous wave type, the second laser chip is set to emit laser beams of pulse type, and the line width of the laser beams of the frequency modulation continuous wave type is smaller than that of the laser beams of the pulse type.

According to another aspect of the present application there is provided a lidar system comprising a TOF lidar and an FMCW lidar, the TOF lidar and the FMCW lidar sharing a multi-channel semiconductor laser of the first aspect.

According to another aspect of the present application, there is provided a vehicle comprising the lidar system of the second aspect.

Drawings

Fig. 1 is a schematic structural diagram of a multi-channel semiconductor laser provided in an embodiment of the present application;

fig. 2 is a schematic top view of a multi-channel semiconductor laser according to an embodiment of the present disclosure;

fig. 3 is a schematic front view of a multi-channel semiconductor laser according to an embodiment of the present disclosure;

fig. 4 is a schematic left-view structural diagram of a multi-channel semiconductor laser according to an embodiment of the present application;

fig. 5 is an exploded schematic view of a multichannel semiconductor laser according to an embodiment of the present application;

fig. 6 is a schematic diagram of a partial structure of a multichannel semiconductor laser according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of another multichannel semiconductor laser provided in this application;

fig. 8 is a schematic top view of another multi-channel semiconductor laser according to an embodiment of the present disclosure;

fig. 9 is a schematic front view of another multi-channel semiconductor laser provided in this embodiment of the present application;

fig. 10 is a schematic structural diagram of a laser radar system according to an embodiment of the present disclosure;

fig. 11 is a schematic structural diagram of another laser radar system provided in an embodiment of the present application;

fig. 12 is a schematic structural diagram of another laser radar system according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Moreover, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Fig. 1 is a schematic structural diagram of a multi-channel semiconductor laser provided in an embodiment of the present application, fig. 2 is a schematic structural diagram of a top view of the multi-channel semiconductor laser provided in the embodiment of the present application, fig. 3 is a schematic structural diagram of a front view of the multi-channel semiconductor laser provided in the embodiment of the present application, fig. 4 is a schematic structural diagram of a left view of the multi-channel semiconductor laser provided in the embodiment of the present application, fig. 5 is a schematic structural diagram of an explosion of the multi-channel semiconductor laser provided in the embodiment of the present application, and fig. 6 is a schematic structural diagram of a part of the multi-channel semiconductor laser provided in the embodiment of the present application, as shown in fig. 1 to fig. 6, the multi-channel semiconductor laser provided in the embodiment of the present application includes a circuit board 10 and at least two laser emitting units 11, the circuit board 10 is electrically connected to the at least two laser emitting units 11, and the circuit board 10 is configured to control laser chips 12 corresponding to the at least two laser emitting units 11 to emit laser beams respectively. The laser chip 12 includes a first laser chip and a second laser chip, the first laser chip is configured to emit a laser beam of a frequency modulated continuous wave type, the second laser chip is configured to emit a laser beam of a pulse type, and a line width of the laser beam of the frequency modulated continuous wave type is smaller than a line width of the laser beam of the pulse type.

Illustratively, the circuit board 10 is provided with a conductive circuit, and the laser chip 12 in the laser emitting unit 11 can be electrically connected to an external driving circuit through the conductive circuit on the circuit board 10, so that the external driving circuit drives the laser chip 12 to emit a laser beam. In some embodiments, the circuit board 10 includes a driving circuit electrically connected to at least two laser emitting units 11, and the driving circuit is configured to directly drive the laser chips 12 corresponding to the laser emitting units 11 to emit laser beams.

The Circuit Board 10 may be a Printed Circuit Board (PCB) to simplify assembly and soldering of electronic products, and is beneficial to reduce product volume, reduce product cost, and improve quality and reliability of electronic devices, but not limited thereto.

In the present application, one laser emitting unit 11 corresponds to one laser chip 12 as an example, that is, the number of the laser chips 12 is the same as that of the laser emitting units 11, therefore, the multi-channel semiconductor laser provided in the embodiment of the present application includes at least two laser chips 12, and the at least two laser chips 12 are configured to emit laser beams of a frequency modulated continuous wave type and laser beams of a pulse type. It is understood that in other embodiments, one laser emitting unit 11 may include more than two laser chips 12.

The laser chip 12 in at least one laser emitting unit 11 is a first laser chip that emits a laser beam of a frequency modulated continuous wave type, so as to meet the light source requirement of the FMCW lidar.

For example, the first laser chip may be used as a laser light source of the FMCW lidar, such that the FMCW lidar may emit a chirped, frequency-modulated continuous wave type laser beam through the first laser chip in the multi-channel semiconductor laser, a frequency of the chirped continuous wave type laser beam may change with time, the emitted chirped continuous wave type laser beam may be reflected by an obstacle to form a first echo beam, the FMCW lidar may receive and process the first echo beam, and a measure of a distance and/or a speed of the obstacle with respect to the FMCW lidar may be obtained by measuring a frequency shift and/or a phase shift of the first echo beam with respect to the chirped continuous wave type laser beam.

The laser chip 12 in at least one laser emitting unit 11 is a second laser chip that emits a pulse-type laser beam, so as to meet the light source requirement of the TOF lidar.

For example, the second laser chip may be used as a laser light source of the TOF lidar, so that the TOF lidar may emit a pulse laser beam through the second laser chip in the multi-channel semiconductor laser, the emitted pulse laser beam may be reflected by an obstacle to form a second echo beam, the TOF lidar may receive and process the second echo beam, and a distance between the TOF lidar and the obstacle may be determined by calculating a delay of a receiving time of the second echo beam relative to an emitting time of the pulse laser beam. Furthermore, the TOF lidar may also determine the velocity of the obstacle by comparing two second echo beams received at different times, e.g. determining the distance between the obstacle and the TOF lidar at different times by two second echo beams received at different times, whereby the change in the distance of the obstacle over time may be used to determine the velocity of the obstacle.

It should be noted that the number of the laser emitting units 11 may be set according to actual requirements, and it is only necessary to ensure that at least one laser emitting unit 11 includes the first laser chip and at least one laser emitting unit 11 includes the second laser chip, which is not limited in this embodiment of the application.

Illustratively, as shown in fig. 1-6, the multi-channel semiconductor laser may include four laser emitting units 11 so as to simultaneously emit four laser beams to form a four-channel semiconductor laser, wherein at least one channel emits a laser beam of a frequency modulated continuous wave type and at least one channel emits a pulsed laser beam.

Illustratively, the line width of the laser beam of the frequency modulated continuous wave type output by the first laser chip is set to be smaller than the line width of the laser beam of the pulse type output by the second laser chip, that is, the line width of the laser beam of the frequency modulated continuous wave type is smaller than the line width of the laser beam of the pulse type, wherein the line width refers to the full width at half maximum of the emission spectrum of the laser source, that is, the width between two corresponding frequencies when the half height of the peak value is reached (sometimes 1/e is also taken). The generation of the line width is mainly influenced by external factors such as spontaneous radiation of excited atoms or ions of the laser, phase noise, mechanical vibration of a resonant cavity, temperature jitter and the like. The smaller the value of the line width, the better the monochromaticity and the stronger the coherence of the laser beam, and the extremely long coherence length is expressed. The FMCW laser radar transmits a laser beam with a frequency modulation continuous wave type and receives a first echo beam reflected by the obstacle, and the distance and the movement speed of the obstacle are detected by demodulating a coherent signal of the laser beam with the frequency modulation continuous wave type and the received first echo beam. Wherein, FMCW laser radar's maximum detection distance is subject to laser beam's coherence length, in order to guarantee that the received signal has good signal to noise ratio, generally require coherence length to be greater than detection distance twice more, consequently, the line width of the laser beam of frequency modulation continuous wave type through setting up first laser chip output is less than pulse type's laser beam, the laser beam of frequency modulation continuous wave type has lower spectral line width promptly, help improving FMCW laser radar's detection distance and sensitivity, realize long-range detection, thereby realize in the laser radar system including TOF laser radar and FMCW laser radar, FMCW laser radar's detection distance is far greater than TOF laser radar's detection distance.

Meanwhile, the detection distance of the TOF laser radar is in direct proportion to the laser emission power of the second laser chip, that is, the longer the detection distance of the TOF laser radar is, the higher the required laser emission power is, and the laser emission power of the narrow linewidth laser chip in the related art is usually smaller, so that in the embodiment, the linewidth of the pulse laser beam output by the second laser chip is wider, which is beneficial to enabling the second laser chip to have larger laser emission power, thereby enabling the TOF laser radar to realize the detection of the longer distance.

In summary, the multichannel semiconductor laser that this application embodiment provided, through the first laser chip that will launch the laser beam of frequency modulation continuous wave type and the second laser chip integration that launches pulse laser beam in a multichannel semiconductor laser, the shortcoming that semiconductor laser chip kind is single among the correlation technique has been overcome, and the linewidth of the laser beam of frequency modulation continuous wave type of first laser chip output is less than the linewidth of the pulse laser beam of second laser chip output, because first laser chip satisfies FMCW lidar's light source demand, second laser chip satisfies TOF lidar's light source demand, make multichannel semiconductor laser can satisfy TOF lidar and FMCW lidar's light source demand simultaneously, thereby can be applied to the lidar system including TOF lidar and FMCW lidar.

Optionally, the first laser chip includes a single-frequency narrow linewidth laser chip, and the second laser chip includes a DFB laser chip.

The single-frequency narrow linewidth laser chip has the characteristics of a single-frequency laser (namely, a single longitudinal mode laser), and is characterized in that an output laser mode meets both a single transverse mode and a single longitudinal mode, only the single longitudinal mode in a resonant cavity vibrates, and output light intensity is in Gaussian distribution. Besides good monochromaticity and directivity of laser, the single-frequency narrow-linewidth laser chip has the characteristics of long coherence length and narrow linewidth which are difficult to achieve by a common laser. Therefore, in this embodiment, by setting the first laser chip to be a single-frequency narrow linewidth laser chip, the laser beam of the frequency modulated continuous wave type emitted by the first laser chip can have a lower spectral linewidth and a longer coherence length, which is helpful for improving the detection distance and sensitivity of the FMCW lidar and realizing long-distance detection.

Illustratively, the second Laser chip may employ a DFB (Distributed Feedback) Laser chip, which may achieve greater Laser emission power than other types of Laser chips, thereby enabling TOF lidar to achieve longer-range detection when the second Laser chip is used as a Laser source of the TOF lidar.

Optionally, the single-frequency narrow-linewidth laser chip includes a single-frequency narrow-linewidth DFB laser chip or a single-frequency narrow-linewidth DBR laser chip.

The DFB laser chip is used for enabling a frequency modulation continuous wave type laser beam emitted by the first laser chip to have a lower spectral line width and a longer coherence length, so that the detection distance and the sensitivity of the FMCW laser radar are improved, and remote detection is realized.

In other embodiments, the first laser chip may also be a DBR (Distributed Bragg Reflector) laser chip, where the DBR laser chip acts as a mirror through a Bragg grating, and a doped fiber is packaged between two Bragg gratings, and gain is provided by pumping the doped fiber in the middle. The DBR laser chip and the DFB laser chip have similar characteristics in narrow line width and high side mode suppression rate, so that the DBR laser chip adopted by the first laser chip can also enable a laser beam of a frequency modulation continuous wave type emitted by the first laser chip to have lower spectral line width and longer coherence length, the detection distance and sensitivity of the FMCW laser radar can be improved, and remote detection can be realized.

It should be noted that the operating wavelengths of the first laser chip and the second laser chip can be set according to actual requirements, for example, the first laser chip can be configured to operate at a wavelength of 1550nm, which is beneficial to achieving narrow linewidth configuration, and the laser beam of the frequency modulated continuous wave type with the wavelength of 1550nm is safer for human eyes; the second laser chip may be configured to operate at a wavelength of 905nm, which facilitates higher power, may enable TOF lidar detection at greater distances, and has better signal-to-noise ratio in snow, fog and rain, but is not so limited and in some embodiments the second laser chip may also be configured to operate at a wavelength of 1550 nm.

Meanwhile, the line widths of the first laser chip and the second laser chip can also be set according to actual requirements, for example, the line width of the frequency modulated continuous wave type laser beam output by the first laser chip is W1, the line width of the pulse laser beam output by the second laser chip is W2, W1 is less than or equal to 500kHz, and W2 is greater than or equal to 1GHz.

The line width W1 of the laser beam of the frequency modulation continuous wave type output by the first laser chip is reasonably set to satisfy that W1 is less than or equal to 500kHz, so that the line width of the laser beam of the frequency modulation continuous wave type output by the first laser chip is smaller, namely the laser beam of the frequency modulation continuous wave type has a lower spectral line width, and when the first laser chip is used as a laser source of an FMCW laser radar, the detection distance and the sensitivity of the FMCW laser radar are improved, and remote detection is realized.

Meanwhile, the line width W2 of the pulse laser beam output by the second laser chip is reasonably set to meet the condition that W2 is larger than or equal to 1GHz, so that the second laser chip has larger laser transmitting power, and the TOF laser radar can realize long-distance detection when the second laser chip is used as a laser source of the TOF laser radar.

The line width W1 of the frequency modulated continuous wave laser beam output by the first laser chip and the line width W2 of the pulse laser beam output by the second laser chip may be set according to actual requirements, for example, W1 is 5kHz, 10kHz, 20kHz, 50kHz, 100kHz, 200kHz or 300kHz, and W2 is 10GHz, 20GHz, 30GHz, 40GHz, 50GHz, 60GHz, 70GHz, 80GHz or 90GHz, but is not limited thereto.

In addition, the laser emission power of the first laser chip and the laser emission power of the second laser chip may also be set according to actual requirements, for example, the laser emission power of the first laser chip is smaller than the laser emission power of the second laser chip.

Compared with a TOF laser radar, the FMCW laser radar is used for reducing the power consumption of a multi-channel semiconductor laser when meeting the requirement of a better signal-to-noise ratio because the laser beam of the frequency modulation continuous wave type required by the FMCW laser radar is a continuous wave signal and has smaller requirement on the laser emission power of a first laser chip and needs to carry out continuous emission power and the required peak power is low.

Simultaneously, TOF laser radar's detection distance is directly proportional with the laser emission power of second laser instrument chip, and TOF laser radar's detection distance is more far away, and required laser emission power is just higher, consequently, laser emission power through setting up the second laser instrument chip is great, can make TOF laser radar realize the detection of further distance.

With continued reference to fig. 1-6, optionally, the laser chips 12 corresponding to at least two laser emitting units 11, respectively, have at least two different heights relative to the surface of the circuit board 10.

The staggered-layer distribution of the laser emitting units 11 can be realized by arranging the laser chips 12 of the at least two laser emitting units 11 with different heights relative to the surface of the circuit board 10, so that the number of channels of the multi-channel semiconductor laser can be increased by using the vertical space above the circuit board 10 when the packaging size of the multi-channel semiconductor laser is not changed; when the number of the channels of the multi-channel semiconductor laser is not changed, the packaging size of the multi-channel semiconductor laser can be reduced.

It should be noted that the staggered structure of the laser emitting units 11 may be set according to actual requirements, as shown in fig. 1 to 6, taking a multichannel semiconductor laser including 4 laser emitting units 11 as an example, 4 laser emitting units 11 may be divided into two groups, each group includes 2 laser emitting units 11, and the heights of each group of laser emitting units 11 are different, so that the vertical space above the circuit board 10 is used to reduce the package size of the multichannel semiconductor laser while increasing the number of channels of the multichannel semiconductor laser, but not limited thereto.

With continued reference to fig. 1 to 6, optionally, the at least two laser emitting units 11 include at least two laser chips 12, the at least two laser emitting units 11 further include a base for supporting the at least two laser chips 12, the base includes a first ceramic substrate 14 and a second ceramic substrate 15 stacked in a vertical direction, the second ceramic substrate 15 is disposed above the first ceramic substrate 14, and a projection of the second ceramic substrate 15 on the first ceramic substrate 14 is located in a rear area of the first ceramic substrate 14 along an exit direction of the laser beam. At least one laser chip 12 is mounted on the surface of the first ceramic substrate 14 on the side facing away from the circuit board in the front region in the emission direction of the laser beam, and at least one laser chip 12 is mounted on the surface of the second ceramic substrate 15 on the side facing away from the circuit board 10.

With continued reference to fig. 1-6, illustratively, a second ceramic substrate 15 is disposed above the first ceramic substrate 14, and the upper surface of the second ceramic substrate 15 has a height difference (approximately equal to the height of the second ceramic substrate 15) with respect to the upper surface of the first ceramic substrate 14.

Illustratively, the second ceramic substrate 15 is located at a rear region of the first ceramic substrate 14 in the emission direction of the laser beam, so that a space for placing the laser chip 12 is left at a front region of the first ceramic substrate 14 in the emission direction of the laser beam, and by mounting at least one laser chip 12 on an upper surface of the first ceramic substrate 14 in the front region of the first ceramic substrate 14 in the emission direction of the laser beam and mounting at least one laser chip 12 on an upper surface of the second ceramic substrate 15, the laser chip 12 disposed on the first ceramic substrate 14 and the laser chip 12 disposed on the second ceramic substrate 15 can have a certain height difference, so that a staggered distribution of at least two laser chips 12 is achieved, which helps to increase the output number of multi-channel semiconductor laser channels and also helps to reduce the packaging volume of the multi-channel semiconductor laser.

Meanwhile, the first ceramic substrate 14 and the second ceramic substrate 15 have good heat conduction efficiency, so that the heat dissipation effect on the laser chip 12 can be enhanced by arranging the laser chip 12 on the first ceramic substrate 14 and the second ceramic substrate 15, thereby avoiding the damage of devices caused by the overhigh working temperature of the laser chip 12 and improving the output stability of the multi-channel semiconductor laser.

It should be noted that the perpendicular projection of the second ceramic substrate 15 on the plane of the first ceramic substrate 14 is located in the first ceramic substrate 14, so that the package size of the multi-channel semiconductor laser can be prevented from being increased.

With continued reference to fig. 1-6, optionally, at least one laser chip 12 mounted on the surface of first ceramic substrate 14 is located at the front end of first ceramic substrate 14 in the exit direction of the laser beam, and at least one laser chip 12 mounted on the surface of second ceramic substrate 15 is located at the front end of second ceramic substrate 15 in the exit direction of the laser beam.

The laser chip 12 on the surface of the first ceramic substrate 14 is arranged at the front end of the first ceramic substrate 14 along the emitting direction of the laser beam, and the laser chip 12 on the surface of the second ceramic substrate 15 is arranged at the front end of the second ceramic substrate 15 along the emitting direction of the laser beam, so that the transmission losses of the laser beams emitted by the laser emitting units 11 on the same ceramic substrate tend to be consistent while the laser emitting directions of the laser chips 12 are ensured to be the same, and the uniformity of the laser beams emitted by the laser emitting units 11 is improved. Simultaneously, set up the laser instrument chip 12 on first ceramic substrate 14 surface in first ceramic substrate 14 same end, still help providing sufficient setting space for second ceramic substrate 15, set up the laser instrument chip 12 on second ceramic substrate 15 surface in second ceramic substrate 15 same end also help reducing the volume of second ceramic substrate 15 to be favorable to realizing multichannel semiconductor laser's miniaturized setting.

With continued reference to fig. 1-6, optionally, when the number of the at least one laser chip 12 mounted on the surface of the first ceramic substrate 14 is an even number, the at least one laser chip 12 is symmetrically distributed on both sides of the front end of the first ceramic substrate 14 along the emission direction of the laser beam, and when the number of the at least one laser chip 12 mounted on the surface of the second ceramic substrate 15 is an even number, the at least one laser chip 12 is symmetrically distributed on both sides of the front end of the second ceramic substrate 15 along the emission direction of the laser beam.

The laser emitting units 11 on the surface of the first ceramic substrate 14 are located on two sides perpendicular to the emitting direction of the laser beam, the number of the laser emitting units 11 on the two sides of the emitting direction of the laser beam is the same, and the positions of the laser emitting units 11 are symmetrically distributed relative to the emitting direction of the laser beam, and the laser emitting units 11 on the first ceramic substrate 14 are symmetrically arranged relative to the emitting direction of the laser beam, so that the transmission loss of the laser beam emitted by the laser emitting units 11 on the first ceramic substrate 14 tends to be consistent, and the uniformity of the laser beam emitted by the laser emitting units 11 on the first ceramic substrate 14 is improved.

Similarly, the laser emitting units 11 on the surface of the second ceramic substrate 15 are located on two sides perpendicular to the emitting direction of the laser beam, the number of the laser emitting units 11 on the two sides of the emitting direction of the laser beam is the same, and the positions of the laser emitting units 11 are symmetrically distributed relative to the emitting direction of the laser beam, and by arranging the laser emitting units 11 on the second ceramic substrate 15 symmetrically relative to the emitting direction of the laser beam, the transmission loss of the laser beam emitted by the laser emitting units 11 on the second ceramic substrate 15 tends to be consistent, so that the uniformity of the laser beam emitted by the laser emitting units 11 on the second ceramic substrate 15 is improved.

With continued reference to fig. 1-6, optionally, at least two laser chips 12 are fixedly mounted on the surfaces of the first ceramic substrate 14 and the second ceramic substrate 15 on the side facing away from the circuit board 10 using conductive silver paste.

The laser chip 12 is fixed by the conductive silver adhesive, the process is simple, the operation is easy, the production efficiency can be improved, and meanwhile, the conductive silver adhesive is used for adhesion and fixation, so that the material deformation, the thermal damage of electronic devices and the formation of internal stress caused by high temperature during welding are avoided. In addition, the conductive silver adhesive can also have better heat conduction effect.

Optionally, the first ceramic substrate 14 and the second ceramic substrate 15 are provided with glue grooves.

The gluing grooves are formed in the first ceramic substrate 14 and the second ceramic substrate 15, so that redundant glue is borne by the gluing grooves when the laser chips 12 on the first ceramic substrate 14 and the second ceramic substrate 15 are fixed, the influence of glue overflow on the transmission of laser beams is avoided, and the transmission quality of the laser beams is improved.

With continued reference to fig. 1-5, optionally, the circuit board 10 includes a receiving cavity 16, and at least two laser emitting units 11 are disposed in the receiving cavity 16.

The circuit board 10 may be provided with a groove structure or a hollow structure to form the accommodating cavity 16, and fig. 1-5 only take the accommodating cavity 16 as the hollow structure for example, but not limited thereto.

In the present embodiment, by disposing at least two laser emitting units 11 in the accommodating cavity 16, it is helpful to reduce the package size of the multi-channel semiconductor laser, and to realize a miniaturized design of the multi-channel semiconductor laser.

In addition, when the accommodating cavity 16 is a hollow structure, the laser emitting unit 11 and the circuit board 10 can be fixedly connected by soldering, so as to improve the reliability of the multi-channel semiconductor laser, but the invention is not limited thereto.

With continued reference to fig. 1-5, optionally, at least two laser emitting units 11 are spaced from the inner wall of the receiving cavity 16.

For example, air may have a better heat insulation effect, and therefore, by setting a certain distance between the at least two laser emitting units 11 and the inner wall of the accommodating cavity 16, that is, an air space exists between the at least two laser emitting units 11 and the circuit board 10, the at least two laser emitting units 11 and the external environment may be isolated from each other, and when the external environment temperature is higher, the influence of the external environment temperature on the laser emitting units 11 may be reduced, which is helpful for improving the output stability of the multi-channel semiconductor laser.

The gap distance between the laser emitting unit 11 and the inner wall of the accommodating cavity 16 may be set according to actual requirements, for example, the gap distance is set to be 0.4mm, 0.5mm, or 0.6mm, but is not limited thereto. It can be understood that if the gap distance is too large, the package size of the multi-channel semiconductor laser is increased, which is not favorable for the miniaturization design of the multi-channel semiconductor laser, and meanwhile, the welding difficulty between the laser emitting unit 11 and the accommodating cavity 16 is also increased; if the clearance distance is too small, a good heat insulation effect cannot be achieved, and the skilled person can set the clearance distance according to actual requirements.

With continued reference to fig. 1-6, optionally, each laser emitting unit 11 further includes a laser monitoring device 18, the laser monitoring devices 18 correspond to the laser chips 12 one to one, and the laser monitoring devices 18 are configured to detect the emission power of the laser beam emitted by the corresponding laser chip 12.

As shown in fig. 1 to 6, the laser emitting unit 11 is provided with laser monitoring devices 18 corresponding to the laser chips 12 one to one, and the laser monitoring devices 18 are electrically connected to the circuit board 10 to transmit monitoring signals to an external circuit, so as to realize a function of monitoring the laser emitting power of the corresponding laser chips 12, and further determine whether the laser emitting power of the laser chips 12 meets the requirements of the laser radar.

With continued reference to fig. 1-6, optionally, the laser monitoring device 18 includes a photosensor chip 181, the photosensor chip 181 being located behind the corresponding laser chip 12 in the direction of the exit of the laser beam.

The Photo sensor chip 181 may be a photodiode chip, and the photodiode (Photo-Diode) chip 181 is a semiconductor device formed by a PN junction, has a unidirectional conductive characteristic, can convert an optical signal into an electrical signal, and has the advantages of good linearity, low noise, low price, light weight, long service life, no need of a high-voltage power supply, and the like, but is not limited thereto.

Illustratively, the photosensor chip 181 is located on a side facing away from the laser emitting end of the laser chip 12. The photodiode chip 181 is disposed on an end surface (rear light-emitting end surface) opposite to an output end of the laser chip 12 (i.e., a laser light-emitting end of the laser chip 12, which is also referred to as a front light-emitting end surface), where a light-emitting power of the rear light-emitting end surface is about 5% to 10% of a light-emitting power of the output end. The photoelectric sensor chip 181 can monitor the laser emission power of the corresponding laser chip 12 by detecting the light emission power of the rear light-emitting end surface and transmitting the light emission power of the rear light-emitting end surface to the circuit board 10.

With continuing reference to fig. 1-6, optionally, the multi-channel semiconductor laser provided in this embodiment of the present application further includes a temperature control unit 19 electrically connected to the circuit board 10, where the temperature control unit 19 includes:

and the temperature monitoring components 191 are installed on the laser emitting units 11 and electrically connected with the circuit board 10, and the temperature monitoring components 191 are arranged to monitor the temperatures of at least two laser emitting units 11.

And the heat dissipation assembly 190 is arranged below the at least two laser emission units 11 along the vertical direction and is electrically connected with the circuit board 10, and the circuit board 10 is arranged to control the heat dissipation assembly 190 to dissipate heat of the at least two laser emission units 11 according to temperature so as to adjust the temperature and keep the temperature within a preset temperature range.

Wherein, in order to avoid the damage of the device caused by the overhigh working temperature of the multi-channel semiconductor laser and improve the stability of the laser output of the device, a temperature control unit 19 is arranged. The temperature monitoring component 191 and the heat dissipation component 190 of the temperature control unit 19 are electrically connected to the circuit board 10 to realize signal transmission between the temperature monitoring component 191 and the heat dissipation component 190 and an external temperature control circuit, the external temperature control circuit is configured to control the heat dissipation component 190 to stabilize the temperature of the laser emission unit 11 within a preset temperature range according to the temperature detected by the temperature monitoring component 191, so that the wavelength of the laser beam emitted by the laser chip 12 of the laser emission unit 11 has high stability.

Illustratively, by disposing the heat dissipation assembly 190 below at least two laser emitting units 11 in the vertical direction, a function of quickly dissipating heat from the laser emitting units 11 can be performed.

With continued reference to fig. 1-5, optionally, the circuit board 10 includes a housing cavity 16, and a temperature control unit 19 is disposed in the housing cavity 16.

The laser emitting unit 11 and the temperature control unit 19 are both arranged in the accommodating cavity 16, so that the packaging size of the multi-channel semiconductor laser is reduced, and the miniaturization design of the multi-channel semiconductor laser is realized. Meanwhile, the laser emission unit 11 and the temperature control unit 19 have a certain air interval with the circuit board 10 in the accommodating cavity 16, so that the influence of the external environment temperature on the laser emission unit 11 and the temperature control unit 19 can be reduced, and the accuracy and the heat dissipation effect of the temperature control unit 19 on the temperature monitoring of the laser emission unit 11 can be improved.

With continued reference to fig. 1-6, optionally, the temperature monitoring assembly 191 includes a thermistor mounted on the second ceramic substrate 15.

Wherein, temperature monitoring subassembly 191 can choose for use thermistor, and thermistor is a sensor resistor, and its resistance value changes along with the change of temperature to the accessible detects the temperature that acquires laser emission unit 11 to thermistor's resistance, and thermistor has advantages such as sensitivity is higher, operating temperature wide range, small, stability is good.

It should be noted that, the temperature monitoring component 191 may also adopt other devices known to those skilled in the art, and only needs to be able to implement the corresponding function, which is not limited in this embodiment of the present application.

Illustratively, the thermistor may be fixed on the second ceramic substrate 15, and since the ceramic substrate has good heat conduction efficiency, by disposing both the laser emitting unit 11 and the temperature monitoring component 191 on the ceramic substrate, the accuracy of temperature monitoring of the laser emitting unit 11 may be improved.

It should be noted that the temperature monitoring component 191 is not limited to be disposed on the second ceramic substrate 15, and in other embodiments, the temperature monitoring component 191 may also be disposed on the first ceramic substrate 14 or other positions, which can be set by a person skilled in the art according to actual needs.

Illustratively, the temperature monitoring assembly 191 includes at least two thermistors respectively mounted on the at least two laser emitting units 11. For example, at least two thermistors and at least two laser emitting units 11 are in a one-to-one correspondence relationship. The present application does not limit the positional relationship between the thermistor and the laser emitting unit 11, and those skilled in the art can set the relationship according to actual needs.

Optionally, the thermistor is fixedly mounted on the surface of the second ceramic substrate 15 facing away from the circuit board 10 by using conductive silver paste.

The thermistor is fixed by conductive silver adhesive, the process is simple, the operation is easy, the production efficiency can be improved, and meanwhile, the conductive silver adhesive is used for adhesion and fixation, so that the material deformation, the thermal damage of an electronic device and the formation of internal stress caused by high temperature during welding are avoided. In addition, the conductive silver adhesive can also have better heat conduction effect.

Optionally, a thermistor is mounted within a predetermined range of the at least one laser chip 12 on the second ceramic substrate 15.

The distance between the thermistor and the laser chip 12 is set within a preset range, so that the distance between the thermistor and the laser chip 12 is short, and the accuracy of monitoring the temperature of the laser emitting unit 11 is improved.

It should be noted that the preset range can be set according to actual requirements, and the embodiment of the present application does not limit this.

With continued reference to fig. 1-6, optionally, the heat dissipation assembly 190 includes a third ceramic substrate 13 and a refrigeration device 192, the third ceramic substrate 13 being positioned between the refrigeration device 192 and the first ceramic substrate 14, the third ceramic substrate 13 being configured to support at least two laser emitting units 11. The refrigeration device 192 is electrically connected to the circuit board 10, and the refrigeration device 192 is configured to dissipate heat of the laser emitting unit 11 through the third ceramic substrate 13 under the control of the circuit board 10 to adjust the temperature to be maintained within a preset temperature range.

The first ceramic substrate 14 is disposed on the third ceramic substrate 13, which is helpful for realizing segmented manufacturing in the preparation process of the multi-channel semiconductor laser, as shown in fig. 6, the third ceramic substrate 13, the first ceramic substrate 14 disposed thereon, and other devices can be transferred to the next preparation process as a whole, thereby facilitating mass production of the multi-channel semiconductor laser.

Meanwhile, the third ceramic substrate 13 has good heat conduction efficiency, so that the heat dissipation effect on the laser chip 12 can be enhanced by positioning the third ceramic substrate 13 between the refrigeration equipment 192 and the first ceramic substrate 14, thereby avoiding the damage of devices caused by the overhigh working temperature of the laser chip 12 and improving the output stability of the multi-channel semiconductor laser.

Optionally, the third ceramic substrate 13 is made of an aluminum nitride ceramic material.

In order to ensure good heat conduction efficiency, an aluminum nitride ceramic material may be used for the third ceramic substrate 13, but is not limited thereto.

Optionally, the refrigeration equipment 192 includes a semiconductor refrigerator.

Among them, a semiconductor Cooler (TEC) transfers heat from one side of the semiconductor Cooler to the other side by using the peltier effect of a semiconductor material, thereby implementing a cooling function. The semiconductor refrigerator is a current transduction type device, can realize high-precision temperature control by controlling input current, is easy to realize remote control, program control and computer control by adding temperature detection and control means, is convenient to form an automatic control system, and has the advantages of quick refrigeration, small power and the like.

It should be noted that, in other embodiments, the refrigeration equipment 192 may also adopt other devices known to those skilled in the art, and only needs to be able to implement the corresponding functions, which is not limited in this embodiment of the application.

With reference to fig. 5, optionally, the multi-channel semiconductor laser provided in this embodiment of the present application further includes at least two laser output units 20, where the at least two laser output units 20 are coupled to the laser chips 12 corresponding to the at least two laser emitting units 11, respectively, in a one-to-one correspondence manner, and each laser output unit 20 is configured to output a laser beam emitted by the corresponding laser chip 12.

For example, as shown in fig. 5, taking a multichannel semiconductor laser including 4 laser emitting units 11 as an example, 4 laser output units 20 are respectively coupled with 4 laser emitting units 11 in a one-to-one correspondence manner, 4 laser output units 20 are configured to respectively output laser beams emitted by the corresponding laser emitting units 11, each laser output unit 20 corresponds to one output channel, and each laser output unit 20 is directly coupled with the corresponding laser emitting unit 11 for output, which is beneficial to reducing the number of devices of the multichannel semiconductor laser and reducing the difficulty of a packaging process.

With continued reference to fig. 5, optionally, each laser output unit 20 includes a lens fiber 201, the lens fiber 201 is coupled to the corresponding laser chip 12, and the lens fiber 201 is configured to output the laser beam emitted by the corresponding laser chip 12 through fiber coupling.

Exemplarily, as shown in fig. 5, taking a multichannel semiconductor laser including 4 laser emitting units 11 as an example, 4 lens optical fibers 201 are respectively arranged in one-to-one correspondence with laser chips 12 of the 4 laser emitting units 11, which is different from a mode in which a laser output unit in the related art adopts coupling output of a plurality of groups of lenses and collimators, and the embodiment of the present application adopts an optical fiber coupling mode of the lens optical fibers 201, so that use of optical components such as collimators is reduced, and thus, the problem of a large volume of a conventional semiconductor laser can be solved.

Optionally, the end face of lensed fiber 201 is a tapered end face.

In this case, by grinding the end of the lensed fiber 201 into a tapered shape, the coupling efficiency between the lensed fiber 201 and the laser chip 12 can be improved, and the insertion loss and return loss between the lensed fiber 201 and the laser chip 12 can be improved.

It should be noted that the end surface shape of the lensed fiber 201 is not limited to the tapered end surface, and in other embodiments, the end surface of the lensed fiber 201 may also be a spherical end surface, a tapered end surface, a quadrangular pyramid end surface, or the like, which is not limited in this embodiment of the present application.

With continued reference to fig. 1-6, optionally, the at least two laser output units 20 further include an optical fiber support assembly disposed in front of the first ceramic substrate 14 and the second ceramic substrate 15 along the laser beam emitting direction X, the optical fiber support assembly being configured to support the lensed optical fiber 201 within a predetermined length at a coupling joint with the at least two laser chips 12.

The optical fiber supporting component is arranged in front of the first ceramic substrate 14 and the second ceramic substrate 15, and when the laser emitting end of the laser chip 12 on the first ceramic substrate 14 and the second ceramic substrate 15 is coupled with the lens optical fiber 201, the optical fiber supporting component can support the lens optical fiber 201 within a preset length of the coupling joint, so that the coupling joint firmness of the lens optical fiber 201 and the laser chip 12 on the first ceramic substrate 14 and the second ceramic substrate 15 can be ensured.

It should be noted that the preset length may be set according to actual requirements, and this is not limited in the embodiment of the present application.

With continued reference to fig. 1-6, optionally, the optical fiber support assembly includes a first optical fiber support 21 and a second optical fiber support 22, along the laser beam emitting direction X, the first optical fiber support 21 is fixedly mounted on the third ceramic substrate 13 and located in front of the first ceramic substrate 14, and the first optical fiber support 21 is configured to support a lens optical fiber 201 mounted within a predetermined length at a coupling connection with at least one laser chip 12 on the first ceramic substrate 14. The second fiber support 22 is fixedly mounted on the first ceramic substrate 14 and located in front of the second ceramic substrate 15, and the second fiber support 22 is configured to support the lens fiber 201 mounted in a predetermined length at a coupling connection with at least one laser chip 12 on the second ceramic substrate 15.

The height of the first fiber support 21 may be the same as the height of the first ceramic substrate 14, and the first fiber support 21 is located on the laser emitting end side of the laser chip 12 on the first ceramic substrate 14. The second fiber holder 22 is fixed on the side of the first ceramic substrate 14 away from the third ceramic substrate 13, the height of the second fiber holder 22 is the same as the height of the second ceramic substrate 15, and the second fiber holder 22 is located on the side of the laser emitting end of the laser chip 12 on the second ceramic substrate 15.

As shown in fig. 5, by providing the first fiber holder 21 having the same height as the first ceramic substrate 14 on the third ceramic substrate 13, the lensed fiber 201 coupled to the laser emitting end of the laser chip 12 on the first ceramic substrate 14 can be supported, so that the coupling between the lensed fiber 201 and the laser chip 12 on the first ceramic substrate 14 can be ensured.

Similarly, the second fiber support 22 with the same height as the second ceramic substrate 15 is disposed on the first ceramic substrate 14, so as to support the lensed fiber 201 coupled to the laser emitting end of the laser chip 12 on the second ceramic substrate 15, thereby ensuring the coupling reliability between the lensed fiber 201 and the laser chip 12 on the second ceramic substrate 15.

For example, after the lensed fiber 201 is coupled to the laser chip 12, the lensed fiber 201 may be fixed to the first fiber holder 21 and the second fiber holder 22 by using an ultraviolet curing adhesive, but is not limited thereto.

It should be noted that, for clarity of illustration of partial structures, the structures of the laser output unit are omitted in fig. 1 to 4, and the structures of the circuit board, the heat dissipation assembly and the laser output unit are omitted in fig. 6, but the scope of protection of the present application is not limited thereto.

1-6, optionally, a first fiber holder 21 is spaced from the first ceramic substrate 14 and a second fiber holder 22 is spaced from the second ceramic substrate 15.

As shown in fig. 1 to 6, a gap is left between the first fiber support 21 and the first ceramic substrate 14, so that the gap can bear excessive glue when the laser chip 12 on the first ceramic substrate 14 and the lens fiber 201 are coupled and fixed, thereby preventing glue overflow from affecting transmission of the laser beam and improving transmission quality of the laser beam. Similarly, a gap is reserved between the second fiber support 22 and the second ceramic substrate 15, so that the gap can bear excessive glue when the laser chip 12 on the second ceramic substrate 15 and the lens fiber 201 are coupled and fixed, the influence on the transmission of the laser beam due to glue overflow is avoided, and the transmission quality of the laser beam is improved.

With continued reference to fig. 1-5, optionally, the circuit board 10 further includes a collecting groove 26, the collecting groove 26 is disposed on one side of the laser emitting ends of the at least two laser chips 12, the collecting groove 12 extends along the transmission direction of the laser beam, and the collecting groove 26 is configured to carry the lens fiber 201.

For example, as shown in fig. 1 to 5, in the emitting direction of the laser beam, a groove, i.e., the collecting groove 12, may be formed in front of the circuit board 10 by a solder-resistance window, and the collecting groove 26 receives the lensed fiber 201 therein, so as to protect the lensed fiber 201.

In addition, when the laser emitting unit 11 is disposed in the accommodating cavity 16, there may be a portion of the laser chip 12 that is lower than the upper surface of the circuit board 10, in this embodiment, the circuit board 10 is provided with the line collecting groove 26, and the lens fiber 201 sequentially passes through the fiber support and the line collecting groove 26 and then extends to the outside, it can be understood that the height of the upper surface of the line collecting groove 26 is less than the height of the upper surface of the circuit board 10, so that the height of the lens fiber 201 can be matched with the height of the laser chip 12 by setting the depth of the line collecting groove 26, and the height of the lens fiber 201 is prevented from being higher than the height of a portion of the laser chip 12, thereby being beneficial to improving the reliability of fiber coupling.

With continued reference to fig. 1-5, optionally, the at least two laser output units 20 further include an optical fiber support component, the optical fiber support component is disposed in front of the first ceramic substrate 14 and the second ceramic substrate 15 along the laser beam emitting direction X, the optical fiber support component is configured to support the lens optical fiber 201 within a preset length at the coupling joint with the at least two laser chips 12, and a distance between the optical fiber support component and the trunking 26 is greater than a preset distance.

Exemplarily, in the process of performing optical fiber coupling between the lens optical fiber 201 and the laser chip 12, the manipulator needs to be used to clamp the lens optical fiber 201, and in this embodiment, the distance between the optical fiber supporting component and the line collecting groove 26 is greater than the preset distance, so as to provide a channel for the manipulator, which is convenient for the manipulator to clamp the lens optical fiber 201 in the optical fiber coupling process, and reduce the difficulty of optical fiber coupling.

Wherein, it can set up according to actual demand to predetermine the distance, as long as can be convenient for the manipulator presss from both sides and gets lens optical fiber 201 can, this application embodiment does not do the limit to this.

With continued reference to fig. 1-5, optionally, the circuit board 10 includes a plurality of positioning holes 31, the plurality of positioning holes 31 being symmetrically distributed along the trunking channel 26.

Illustratively, positioning holes 31 are reserved around the circuit board 10, and the positioning holes 31 may be configured as positioning housings.

The shape of the positioning hole 31 may be a rectangle as shown in fig. 1 to 5, but is not limited thereto, and the positioning hole 31 may also be a circle, a triangle, and the like, which is not limited in the embodiment of the present invention.

Fig. 7 is a schematic structural diagram of another multichannel semiconductor laser provided in this embodiment, fig. 8 is a schematic structural diagram of a top view of another multichannel semiconductor laser provided in this embodiment, and fig. 9 is a schematic structural diagram of a front view of another multichannel semiconductor laser provided in this embodiment, where fig. 7 to 9 are schematic structural diagrams of the multichannel semiconductor laser in a packaged state, as shown in fig. 1 to 9, optionally, the circuit board 10 further includes a plurality of bonding pads 27 disposed around the at least two laser emitting units 11 and a plurality of gold fingers 28 located at an edge of the circuit board 10, the bonding pads 27 and the gold fingers 28 are electrically connected in a one-to-one correspondence, and the at least two laser emitting units 11 are electrically connected to the plurality of bonding pads 27.

For example, as shown in fig. 1 to 5, a plurality of pads 27 are disposed on the circuit board 10, the plurality of pads 27 are respectively connected with a plurality of gold fingers 28 on the outer ring of the circuit board 10 in a one-to-one correspondence manner, and the laser emitting unit 11 and the pads 27 on the circuit board 10 can be electrically connected by gold wire bonding. The gold finger 28 is electrically connected to an external driving circuit, so that the laser emitting unit 11 can perform signal transmission with the external driving circuit, and the external driving circuit can drive and control the laser emitting unit 11.

For example, as shown in fig. 1-5, the heat sink assembly 190 may be connected to the pads 27 to enable signal transmission between the heat sink assembly 190 and the circuit board 10 through the pads 27.

With continued reference to fig. 7-9, optionally, the multi-channel semiconductor laser provided by the embodiment of the present application further includes a housing 30, the housing 30 is configured to receive the laser emitting unit 11 and the main body portion of the circuit board 10, and the plurality of gold fingers 28 and part of the light collecting grooves 26 protrude out of the housing 30.

The laser emitting unit 11 and the main body of the circuit board 10 are accommodated by the housing 30, so as to protect the laser emitting unit 11 and the main body of the circuit board 10.

With continued reference to fig. 7-9, optionally, the housing 30 includes a bottom shell 301 and an upper cover 302, the bottom shell 301 and the upper cover 302 are respectively located at two sides of the circuit board 10, and the bottom shell 301 and the upper cover 302 are located by a plurality of locating holes 31.

Illustratively, as shown in fig. 7-9, the upper cover 302 is located on the upper surface side of the circuit board 10, the bottom cover 301 is located on the lower surface side of the circuit board 10, and a cavity is formed between the bottom cover 301 and the upper cover 302 to accommodate the laser emitting unit 11 and the main portion of the circuit board 10, so as to protect the laser emitting unit 11 and the main portion of the circuit board 10.

With reference to fig. 1 to 9, positioning holes 31 are reserved around the circuit board 10, the positioning holes 31 may be disposed on the edge of the circuit board 10, and positioning protrusions (not shown) are disposed on the bottom case 301 and the upper cover 302, and are correspondingly connected to the positioning holes 31, so as to position the bottom case 301 and the upper cover 302 on the circuit board 10.

Illustratively, when assembling the bottom case 301 and the upper cover 302 with the circuit board 10, the positioning bosses on the bottom case 301 and the upper cover 302 may be inserted into the positioning holes 31 on the circuit board 10, and then the gaps between the bottom case 301 and the circuit board 10 and between the upper cover 302 and the circuit board 10 are filled with glue, respectively, thereby forming a hermetic package.

Optionally, the housing 30 includes a metal housing, and the bottom case 301 is made of an oxygen-free copper material.

The housing 30 is a metal housing, which can shield the laser emitting unit 11 from other electronic circuits, thereby improving the stability of the multi-channel semiconductor laser.

Illustratively, the bottom chassis 301 may be made of an oxygen-free copper material having good thermal conductivity, but is not limited thereto.

Optionally, the refrigeration device 192 includes a hot side facing the bottom case 301 and fixed on the bottom case 301, and a cold side connected to the third ceramic substrate 13.

Taking the refrigeration device 192 as an example, the refrigeration device 192 is disposed on the surface of the third ceramic substrate 13 away from the laser emitting unit 11, the hot surface of the refrigeration device 192 faces the bottom case 301, and the heat at the hot surface of the refrigeration device 192 is facilitated to be dissipated through the casing 30 by connecting the hot surface of the refrigeration device 192 with the metal casing.

Optionally, the heat dissipation assembly 190 is fixed on the bottom case 301 by welding.

For example, the heat sink assembly 190 may be soldered to the bottom chassis 301 using solder. Wherein, the solder has good heat conductivity, makes radiator unit 190 and drain pan 301 closely laminate through the welded mode, is favorable to radiating away through drain pan 301 with the heat of radiator unit 190 hot side department.

For example, as shown in fig. 1 to 5, taking the heat dissipation assembly including a semiconductor cooler as an example, the third ceramic substrate 13 may be fixed on the cold surface of the semiconductor cooler by soldering, so that the semiconductor cooler is in sufficient contact with the surface of the third ceramic substrate 13 away from the laser emitting unit 11, and the third ceramic substrate 13 has good heat conduction efficiency, thereby achieving the effect of quickly dissipating heat from the laser emitting unit 11 on the third ceramic substrate 13.

With continued reference to fig. 7-9, optionally, bottom shell 301 is formed with mounting holes 32.

For example, the mounting holes 32 may be located around the bottom case 301, and the mounting holes 32 are configured to mount the multi-channel semiconductor laser on another debugging platform for debugging, but are not limited thereto.

The shape of the mounting hole 32 may be a circle as shown in fig. 7-9, but is not limited thereto, and the mounting hole 32 may also be a rectangle, a triangle, etc., which is not limited in the embodiments of the present application.

Illustratively, as shown in fig. 1-9, the pads 27 are located inside the housing 30, and the pads 27 are small in size, so that the conventional housing specifications of the semiconductor laser can be adopted, i.e., the circuit board 10 can be directly arranged in a standard housing under the conventional specifications, so as to reduce the production cost.

Illustratively, as shown in fig. 1-9, the gold finger 28 is located outside the housing 30, so as to facilitate the connection between the gold finger 28 and the external circuit, wherein the gold finger 28 has the characteristics of being not easy to oxidize and stable in contact resistance, so as to ensure the connection stability of the gold finger 28.

For example, in order to ensure good heat conduction efficiency, the first ceramic substrate 14 and the second ceramic substrate 15 may use an aluminum nitride ceramic material, but not limited thereto.

With continued reference to fig. 1-6, the perpendicular projections of the first ceramic substrate 14 and the second ceramic substrate 15 on the plane of the third ceramic substrate 13 are located within the third ceramic substrate 13, thereby avoiding increasing the package size of the multi-channel semiconductor laser.

It should be noted that the base is not limited to the first ceramic substrate 14 and the second ceramic substrate 15, and the number of the ceramic substrates in the base, the height of the ceramic substrates, and the combination position structure of the ceramic substrates are not limited to the above embodiments, and those skilled in the art can set the base according to actual requirements.

Based on the same inventive concept, the embodiment of the present application further provides a laser radar system, fig. 10 is a schematic structural diagram of a laser radar system provided by the embodiment of the present application, as shown in fig. 10, the laser radar system 40 includes a TOF laser radar 41 and an FMCW laser radar 42, and the TOF laser radar 41 and the FMCW laser radar 42 share any one of the multi-channel semiconductor lasers 60 provided by the above embodiments.

Illustratively, the FMCW lidar 42 is configured to output a frequency modulated continuous wave type laser beam emitted by the multi-channel semiconductor laser 60 and to receive a first return beam of the frequency modulated continuous wave type laser beam reflected back through an obstacle. The TOF laser radar 41 is arranged to output a pulse laser beam emitted by the multichannel semiconductor laser 60 and to receive a second echo beam reflected by the pulse laser beam back through an obstacle.

Wherein, TOF lidar 41 and FMCW lidar 42 share any one of the multi-channel semiconductor lasers 60 provided by the above embodiments, and the same or corresponding structures and explanations of terms as those of the above embodiments are not repeated herein.

Fig. 11 is a schematic structural diagram of another laser radar system according to an embodiment of the present application, as shown in fig. 11, optionally, the TOF laser radar 41 and the FMCW laser radar 42 further include a first scanning module 43, the wavelengths of the frequency modulated continuous wave laser beam and the pulse laser beam are different, the first scanning module 43 is configured to combine the frequency modulated continuous wave laser beam and the pulse laser beam, and output a combined laser beam, the scanning tracks corresponding to the frequency modulated continuous wave laser beam and the pulse laser beam are overlapped, and input a first echo beam corresponding to the wavelength of the frequency modulated continuous wave laser beam reflected by the combined laser beam reaching the surface of the obstacle to the FMCW laser radar 42, and input a second echo beam corresponding to the wavelength of the pulse laser beam to the TOF laser radar 41.

After passing through the first scanning module 43, the pulse laser beam emitted by the TOF laser radar 41 and the frequency modulated continuous wave laser beam emitted by the FMCW laser radar 42 have coincident scanning tracks to an obstacle, in a ranging period, the scanning track of the pulse laser beam is a plurality of continuous points, the scanning track of the frequency modulated continuous wave laser beam is a line, and the tracks of the plurality of continuous points coincide with the track of the line. In this embodiment, the TOF lidar 41 and the FMCW lidar 42 can be synchronously scanned by a set of first scanning modules 43.

Optionally, the wavelengths of the laser beams of the pulse laser beam type and the frequency modulated continuous wave type are different, so that the interference phenomenon caused by the fact that the laser beams of the pulse laser beam type and the frequency modulated continuous wave type are consistent or have small difference can be avoided, further, the reduction of the measurement precision of the TOF laser radar 41 and the FMCW laser radar 42 is avoided, and the performance of a laser radar system is improved.

Fig. 12 is a schematic structural diagram of another lidar system according to an embodiment of the present disclosure, as shown in fig. 12, optionally, TOF lidar 41 further includes a second scanning module 65, FMCW lidar further includes a third scanning module 66, TOF lidar forms a first scanning field of view FOV1 by emitting a laser beam of a pulse type to the second scanning module 65, and FMCW lidar 42 forms a second scanning field of view FOV2 by emitting a laser beam of a frequency modulated continuous wave type to the third scanning module 66. The second scan view field FOV2 is smaller than the first scan view field FOV1, the detection distance of the second scan view field FOV2 is larger than the detection distance of the first scan view field FOV1, and the ratio of the resolution of the second scan view field FOV2 to the resolution of the first scan view field FOV1 is equal to the ratio of the detection distance of the second scan view field FOV2 to the detection distance of the first scan view field FOV 1.

The second scanning module 65 and the third scanning module 66 may be scanning galvanometers, and the wavelength of the pulsed laser beam may be different from the wavelength of the frequency modulated continuous wave type laser beam.

It should be noted that the areas of the scanning fields of view of the second scanning module 65 and the third scanning module 66 can be controlled to scan in a manner well known to those skilled in the art, for example, the controlled scanning can be performed by a signal processing module (not shown in the figure). Wherein, the signal processing module can set the ratio of the detection distance of the second scan view field FOV2 to the detection distance of the first scan view field FOV1 to be equal to the ratio of the resolution of the second scan view field FOV2 to the resolution of the first scan view field FOV1, so that the first scan view field FOV1 and the second scan view field FOV2 have the same identification effect. For example, when the detecting distance of the second scan field of view FOV2 is 2 times the detecting distance of the first scan field of view FOV1, the ratio of the resolution of the second scan field of view FOV2 to the resolution of the first scan field of view FOV1 is also 2, and at this time, the second scan field of view FOV2 and the first scan field of view FOV1 have the same point cloud density, i.e., the recognition effect of the second scan field of view FOV2 and the first scan field of view FOV1 is the same.

In some embodiments, the signal processing module may also calculate the point cloud density of the first scanning field of view FOV1 from the point cloud rate of the TOF lidar 41 and the size of the first scanning field of view FOV 1; the size of the second scan field of view FOV2 is controlled in accordance with the point cloud density of the first scan field of view FOV1, the point cloud rate of the FMCW lidar 42, the ratio of the point cloud density of the second scan field of view FOV2 to the first scan field of view FOV1, and the aspect ratio of the first scan field of view FOV1 on the orthogonal projection plane of the first scan field of view FOV 1. Illustratively, after calculating the size of the second scan field of view FOV2, the signal processing module controls the third scanning module 66 to scan in the corresponding pitch angle and horizontal angle, so as to control the size of the second scan field of view FOV2.

For example, if the first scan field FOV1 is in the range of 120 degrees × 25 degrees, i.e., the horizontal field angle is 120 degrees, the pitch field angle is 25 degrees, and the point cloud rate of the TOF lidar 41 is 250000 points per frame, then the point cloud density of the first scan field FOV1 is about 83 points per square degree (resolution), and if the second scan field FOV2 requires 2 times the point cloud density of the first scan field FOV1, i.e., 166 points per square degree, and the point cloud rate of the FMCW lidar 42 is 10000 points per frame, then the size of the second scan field FOV2 is 10000/166 ≈ 60 square degrees, and the second scan field FOV2 should be 17 degrees × 3.4 degrees, i.e., the horizontal field angle is 17 degrees and the pitch field angle is 3.4 degrees, in accordance with the ratio of the first scan field FOV1 of 120 = 25 =5. Therefore, the defect of insufficient point cloud rate of the FMCW laser radar 42 is overcome, and therefore, the FMCW laser radar has higher and almost the same resolution in a short-distance view field and a long-distance view field. Further, an obstacle having a long distance can be detected by the second scan field FOV2, and an obstacle having a short distance can be detected by the first scan field FOV 1.

It will be appreciated that the maximum detection range of TOF lidar 41 is typically 200 meters and the detection range of FMCW lidar 42 is typically 500 meters, and further that TOF lidar 41 may be used for detection when detecting obstacles within 200 meters and FMCW lidar 42 may be used for detection when detecting obstacles outside 200 meters.

Optionally, the second scanning field of view FOV2 is located in the first scanning field of view FOV1, and the center of the second scanning field of view FOV2 coincides with the center of the first scanning field of view FOV 1.

On the orthogonal projection planes of the first scan field of view FOV1 and the second scan field of view FOV2, the aspect ratio of the second scan field of view FOV2 is the same as the aspect ratio of the first scan field of view FOV 1.

It should be noted that, the center of the second scan view FOV2 coincides with the center of the first scan view FOV1, and the aspect ratios of the two are the same, and when the laser radar system 40 is applied to a vehicle, the FMCW laser radar 42 may be configured in the central range right in front of the vehicle, so that the distance in the central range right in front of the vehicle is detected to be longer, and the resolution is the same as that of the TOF laser radar 41, and the target recognition effect can be the same as that of the TOF laser radar 41, which is favorable for driving safety.

Based on the same inventive concept, the embodiment of the present application further provides a vehicle, where the vehicle includes any one of the lidar systems provided in the above embodiments, and the structures and explanations of terms that are the same as or corresponding to those in the above embodiments are not repeated herein.

Claims

1. A multi-channel semiconductor laser comprises a circuit board and at least two laser emission units;

2. The multi-channel semiconductor laser of claim 1, wherein the first laser chip comprises a single frequency narrow linewidth laser chip and the second laser chip comprises a DFB laser chip.

3. The multi-channel semiconductor laser of claim 2, wherein the single-frequency narrow-linewidth laser chip comprises a single-frequency narrow-linewidth DFB laser chip or a single-frequency narrow-linewidth DBR laser chip.

4. A multi-channel semiconductor laser as claimed in any of claims 1-3 wherein at least two of the laser emitting units have respective corresponding laser chips at least two different heights relative to the surface of the circuit board.

5. The multi-channel semiconductor laser as claimed in claim 4, wherein the at least two laser emitting units comprise at least two laser chips, the at least two laser emitting units further comprise a pedestal for supporting the at least two laser chips, the pedestal comprises a first ceramic substrate and a second ceramic substrate which are stacked in a vertical direction, the second ceramic substrate is disposed above the first ceramic substrate, and a projection of the second ceramic substrate on the first ceramic substrate is located in a rear region of the first ceramic substrate in an exit direction of the laser beam;

the laser chip is arranged on the front area of the first ceramic substrate along the emitting direction of the laser beam and on the surface of one side of the first ceramic substrate, which is far away from the circuit board, and the laser chip is arranged on the surface of the second ceramic substrate, which is far away from the circuit board.

6. The multi-channel semiconductor laser of claim 5,

at least one laser chip mounted on the surface of the first ceramic substrate is located at the front end of the first ceramic substrate in the emission direction of the laser beam;

and at least one laser chip arranged on the surface of the second ceramic substrate is positioned at the front end of the second ceramic substrate along the emergent direction of the laser beam.

7. The multi-channel semiconductor laser of claim 6,

when the number of the at least one laser chip mounted on the surface of the first ceramic substrate is even, the at least one laser chip is symmetrically distributed on two sides of the front end of the first ceramic substrate along the emitting direction of the laser beam;

and when the number of the at least one laser chip mounted on the surface of the second ceramic substrate is even, the at least one laser chip is symmetrically distributed on two sides of the front end of the second ceramic substrate along the emitting direction of the laser beam.

8. A multi-channel semiconductor laser according to any of claims 5-7, wherein at least two of the laser chips are fixedly mounted on the surfaces of the first and second ceramic substrates on the side facing away from the circuit board using conductive silver paste.

9. The multi-channel semiconductor laser of any of claims 5-7, wherein the first and second ceramic substrates are provided with glue trenches.

10. The multi-channel semiconductor laser of claim 1,

the circuit board comprises an accommodating cavity, and at least two laser emission units are arranged in the accommodating cavity.

11. The multi-channel semiconductor laser of claim 10, wherein at least two of the lasing units are spaced from an inner wall of the containment cavity.

12. A multi-channel semiconductor laser as claimed in any of claims 1-3 wherein each of the laser emitting units further comprises a laser monitoring device, the laser monitoring devices being in one-to-one correspondence with the laser chips, the laser monitoring devices being arranged to detect the emitted power of the laser beam emitted by the corresponding laser chip.

13. A multi-channel semiconductor laser as claimed in claim 12 wherein the laser monitoring device comprises a photosensor chip located behind the corresponding laser chip in the direction of exit of the laser beam.

14. The multi-channel semiconductor laser of claim 5, further comprising a temperature control unit electrically connected to the circuit board, the temperature control unit comprising:

the temperature monitoring assembly is arranged on the laser emission units and electrically connected with the circuit board, and is used for monitoring the temperatures of at least two laser emission units;

the heat dissipation assembly is arranged below the at least two laser emission units in the vertical direction and electrically connected with the circuit board, and the circuit board is arranged to control the heat dissipation assembly to dissipate heat of the at least two laser emission units according to the temperature so as to adjust the temperature to be kept within a preset temperature range.

15. The multi-channel semiconductor laser of claim 14, wherein the circuit board includes a housing cavity, the temperature control unit being disposed in the housing cavity.

16. A multi-channel semiconductor laser as claimed in claim 14 wherein the temperature monitoring assembly includes a thermistor mounted on the second ceramic substrate.

17. A multi-channel semiconductor laser as claimed in claim 16 wherein the thermistor is fixedly mounted on a surface of the second ceramic substrate on a side facing away from the circuit board using conductive silver paste.

18. A multi-channel semiconductor laser as claimed in claim 16 or 17 wherein the thermistor is mounted within a predetermined range of at least one of the laser chips on the second ceramic substrate.

19. The multi-channel semiconductor laser of claim 14, wherein the heat dissipation assembly comprises a third ceramic substrate and a refrigeration device, the third ceramic substrate being positioned between the refrigeration device and the first ceramic substrate, the third ceramic substrate being configured to support at least two of the laser emitting units; the refrigeration equipment is electrically connected with the circuit board, and the refrigeration equipment is arranged to dissipate heat of the laser emission unit through the third ceramic substrate under the control of the circuit board so as to adjust the temperature to be kept within a preset temperature range.

20. The multi-channel semiconductor laser of claim 19, wherein the third ceramic substrate is made of an aluminum nitride ceramic material.

21. A multi-channel semiconductor laser as claimed in claim 19 wherein the refrigeration device comprises a semiconductor refrigerator.

22. The multi-channel semiconductor laser of claim 19, further comprising at least two laser output units; the laser output units are coupled with the laser chips respectively corresponding to the laser emission units in a one-to-one correspondence manner, and each laser output unit is set to output the laser beams emitted by the corresponding laser chip.

23. A multi-channel semiconductor laser as claimed in claim 22 wherein each of the laser output units includes a lensed fiber coupled to the corresponding laser chip, the lensed fiber configured to fiber-couple out the laser beam emitted by the corresponding laser chip.

24. A multi-channel semiconductor laser as claimed in claim 23 wherein the end facet of the lensed fiber is a tapered end facet.

25. The multi-channel semiconductor laser of claim 23, wherein at least two of the laser output units further comprise a fiber support assembly disposed in front of the first and second ceramic substrates along the laser beam exit direction, the fiber support assembly configured to support the lensed fiber within a predetermined length of a coupling connection with at least two of the laser chips.

26. The multi-channel semiconductor laser of claim 25, wherein the fiber support assembly comprises a first fiber support and a second fiber support;

along the laser beam emergent direction, a first optical fiber support is fixedly arranged on the third ceramic substrate and is positioned in front of the first ceramic substrate, and the first optical fiber support is arranged to support and install the lens optical fiber within a preset length of the coupling joint of at least one laser chip on the first ceramic substrate;

the second optical fiber support is fixedly arranged on the first ceramic substrate and positioned in front of the second ceramic substrate, and the second optical fiber support is arranged to support the lensed optical fiber arranged in a preset length at the coupling joint of the at least one laser chip on the second ceramic substrate.

27. The multi-channel semiconductor laser of claim 26, wherein the first fiber support has a gap with the first ceramic substrate and the second fiber support has a gap with the second ceramic substrate.

28. The multi-channel semiconductor laser of claim 23, wherein the circuit board further comprises a collection groove disposed on a side of laser emission ends of at least two of the laser chips and extending along a transmission direction of the laser beam, the collection groove configured to carry the lensed fiber.

29. The multi-channel semiconductor laser of claim 28,

the at least two laser output units further comprise optical fiber supporting components, the optical fiber supporting components are arranged in front of the first ceramic substrate and the second ceramic substrate along the laser beam emergent direction, and the optical fiber supporting components are arranged to support the lens optical fibers within a preset length of the coupling connection position of the optical fiber supporting components and the at least two laser chips;

the distance between the optical fiber supporting component and the line concentration groove is larger than a preset distance.

30. The multi-channel semiconductor laser of claim 28, wherein the circuit board includes a plurality of positioning holes, the plurality of positioning holes being symmetrically distributed along the collection line slot.

31. The multi-channel semiconductor laser of claim 30, wherein the circuit board further comprises a plurality of bonding pads disposed around at least two of the laser emitting units and a plurality of gold fingers located at an edge of the circuit board, the plurality of bonding pads and the plurality of gold fingers being electrically connected in a one-to-one correspondence, at least two of the laser emitting units being electrically connected to the bonding pads.

32. A multi-channel semiconductor laser as claimed in claim 31 further comprising a housing configured to receive at least two of the laser emitting units and a body portion of the circuit board, a plurality of the gold fingers and a portion of the collection grooves extending out of the housing.

33. A multi-channel semiconductor laser as claimed in claim 32 wherein the housing comprises a bottom shell and a top cover, the bottom shell and the top cover being located on either side of the circuit board, the bottom shell and the top cover being positioned by a plurality of the positioning holes.

34. A multi-channel semiconductor laser as claimed in claim 33 wherein the housing comprises a metal housing and the bottom case is made of an oxygen free copper material.

35. The multi-channel semiconductor laser of claim 33, wherein the refrigeration device comprises a hot side and a cold side, the hot side facing and secured to the bottom case, the cold side connected to the third ceramic substrate.

36. A multi-channel semiconductor laser as claimed in claim 35 wherein the heat sink assembly is secured to the bottom housing by soldering.

37. The multi-channel semiconductor laser of claim 33, wherein the bottom case defines a mounting hole.

38. A lidar system comprising a TOF lidar and an FMCW lidar sharing a multi-channel semiconductor laser as claimed in any one of claims 1 to 37.

39. The lidar system of claim 38, wherein the TOF lidar and the FMCW lidar further comprise a first scanning module, the wavelength of the frequency modulated continuous wave laser beam and the wavelength of the pulse laser beam are different, the first scanning module is configured to combine the frequency modulated continuous wave laser beam and the pulse laser beam, output a combined laser beam, the frequency modulated continuous wave laser beam and the scanning trajectory corresponding to the pulse laser beam are overlapped, and input a first echo beam corresponding to the wavelength of the frequency modulated continuous wave laser beam reflected by the combined laser beam reaching an obstacle surface to the FMCW lidar, and input a second echo beam corresponding to the wavelength of the pulse laser beam to the TOF lidar.

40. The lidar system of claim 38, wherein the TOF lidar further comprises a second scanning module, the FMCW lidar further comprises a third scanning module, the TOF lidar forms a first scan field of view by emitting the pulsed type laser beam to the second scanning module, the FMCW lidar forms a second scan field of view by emitting the frequency modulated continuous wave type laser beam to the third scanning module;

the second scanning view field is smaller than the first scanning view field, the detection distance of the second scanning view field is larger than the detection distance of the first scanning view field, and the ratio of the resolution of the second scanning view field to the resolution of the first scanning view field is equal to the ratio of the detection distance of the second scanning view field to the detection distance of the first scanning view field.

41. A vehicle comprising the lidar system of any of claims 38-40.