Laser transceiving device

Abstract

A laser transceiving device, relating to the technical field of laser ranging. The device comprises a support (10), and a semiconductor laser die (1), a packaging carrier (2), a collimating lens barrel (3), a collimating lens (4), a receiving lens (5), a reflection table (6) and a photoelectric detection chip (8) which are mounted on the support (10). The device uses an independent semiconductor laser die, thereby simplifying a packaging structure, reducing the volume and costs, and also effectively avoiding nonlinearity of power monitoring caused by precise positional requirements and a thermal coupling effect when the semiconductor laser die and a power monitoring photodiode die are packaged at the same time. The device integrates a high-gain detection die and an ordinary photodiode die together, without it being necessary to separately package a power monitoring photodiode, thereby further reducing the volume and costs and improving the performance.

Description

A laser transceiver TECHNICAL FIELD

[0001] The present application relates to the field of laser ranging technology, and particularly relates to a laser transceiver. BACKGROUND

[0002] When the laser ranging device emits laser, the emitted laser needs to be modulated, and the emission power needs to be controlled. When the traditional laser ranging needs to stabilize the emission power of the laser diode, a composite packaged semiconductor laser is used, which integrates the laser diode and the photodiode for monitoring the laser power. With this kind of semiconductor laser, the laser diode and the photodiode need to be packaged on the carrier at the same time, and the photodiode and the laser diode need to be packaged according to a certain spacing and position, so as to effectively monitor the emission power of the laser diode, which inevitably leads to a complex packaging structure and process, a large volume, and is not conducive to integration, increases the cost, and limits its application to occasions with high requirements on volume. The photodiode and the laser diode both belong to temperature-sensitive devices, and when they are packaged together, the heat effect generated by the laser diode when emitting light will directly affect the photocurrent of the photodiode, resulting in poor linearity of the emission power monitoring. SUMMARY

[0003] The purpose of the present application is to provide a laser transceiver that simplifies the laser transceiver structure, greatly reduces the volume of the semiconductor laser while improving the detection performance, improves the integration level, and reduces the volume and cost.

[0004] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0005] A laser transceiver, comprising a support, and a semiconductor laser die, a packaging carrier, a collimating lens barrel, a collimating lens, a receiving lens, a reflecting platform and a photodetector chip mounted on the support; the packaging carrier is provided with positive and negative electrodes, and the positive and negative electrodes of the semiconductor laser die are respectively connected to the corresponding electrodes of the packaging carrier; the collimating lens barrel is sleeved outside the semiconductor laser die, the collimating lens barrel wall is provided with a light passing hole, the collimating lens is mounted on the collimating lens barrel port and is opposite to the object to be detected, and the reflecting platform is located on the extension line of the connecting line between the semiconductor laser die and the light passing hole; the photodetector chip is integrated with a high-gain detection die and a common photodiode die, and the receiving lens is opposite to the high-gain detection die.

[0006] Further, the external modulation signal is input through the positive and negative electrodes of the packaging carrier, and then transmitted to the semiconductor laser chip through the electrodes of the semiconductor laser chip, and the collimated semiconductor laser chip emits laser carrying the modulation signal; most of the laser is collimated by the collimating lens, reflected by the detected object, collected by the receiving lens, and then gathered to the high-gain detection chip to form an external echo electric signal; a small part of the laser is scattered to the reflecting platform through the light hole without collimation, and then reflected by the reflecting platform to irradiate the high-gain detection chip and the ordinary photodiode chip, to form an internal reference electric signal on the high-gain detection chip, and a direct current electric signal proportional to the emission power of the laser on the ordinary photodiode chip.

[0007] Further, the high-gain detection chip is any one of an avalanche photodiode, a single-photon avalanche diode or a silicon photodiode, and the ordinary photodiode chip is an ordinary photodiode.

[0008] Further, the photoelectric detection chip further integrates a medium-low gain detection chip, which is located between the high-gain detection chip and the ordinary photodiode chip.

[0009] Further, the external modulation signal is input through the positive and negative electrodes of the packaging carrier, and then transmitted to the semiconductor laser chip through the electrodes of the semiconductor laser chip, and the collimated semiconductor laser chip emits laser carrying the modulation signal; most of the laser is collimated by the collimating lens, reflected by the detected object, collected by the receiving lens, and then gathered to the high-gain detection chip to form an external echo electric signal; a small part of the laser is scattered to the reflecting platform through the light hole without collimation, and then reflected by the reflecting platform to irradiate the high-gain detection chip and the ordinary photodiode chip, to form an internal reference electric signal on the high-gain detection chip, and a direct current electric signal proportional to the emission power of the laser on the ordinary photodiode chip.

[0010] Further, the medium-low gain detection chip is an ordinary photodiode.

[0011] Further, the high-gain detection chip and the medium-low gain detection chip use the same bias driving voltage.

[0012] Further, before the transceiver device formally measures the distance, a standard emission power of the laser emitted by the semiconductor laser chip is set, and the standard emission power includes the following operations: Sa, the semiconductor laser chip emits laser with a preset initial emission power, the direct current electric signal is monitored, the laser emission power is adjusted until the direct current electric signal is equal to or greater than a preset value, and the current laser emission power is recorded as an adjusted emission power; Sb, the laser is emitted with the adjusted emission power, the signal-to-noise ratio is obtained according to the external echo electric signal and the internal reference electric signal, and the standard emission power is set according to the signal-to-noise ratio.

[0013] Further, when the ranging method of the transceiver device adopts the direct pulse method, a time difference is obtained based on the time when the internal reference electrical signal is received by the photoelectric detection chip and the time when the external echo electrical signal is received by the photoelectric detection chip, and then the distance of the detected object is calculated through the time difference.

[0014] Further, when the ranging method of the transceiver device adopts the phase pulse method, a phase difference is obtained based on the initial phase of the internal reference electrical signal and the terminal phase of the external echo electrical signal, and then the distance of the detected object is calculated through the phase difference.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] The present application adopts an independent semiconductor laser tube core, simplifies the packaging structure, reduces the volume and cost, and also effectively avoids the precise requirement for position and the thermal coupling effect when the semiconductor laser tube core and the power monitoring photodiode tube core are simultaneously packaged, which leads to the nonlinearity of power monitoring. The present application integrates the high-gain detection tube core and the ordinary photodiode tube core together, without the need for separately packaging the power monitoring photodiode, thereby improving the performance while further reducing the volume and cost.

[0017] The photoelectric detection chip of the present application integrates the high-gain detection tube core, the medium-low gain detection tube core and the ordinary photodiode tube core, and the laser emitted by the semiconductor laser tube core forms three signals. The direct current signal is used for regulating and controlling the emission power of the laser, and the internal reference electrical signal and the external echo electrical signal are used for ranging, which greatly improves the ranging efficiency. Through the high-gain detection tube core and the medium-low gain detection tube core, without the need for a separate signal gain control device, the emission power requirement of different ranging can be met, which expands the applicability while ensuring the stability. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 is a first structure schematic diagram of the present application.

[0019] Fig. 2 is a second structure schematic diagram of the present application.

[0020] Fig. 3 is one of the integrated structures of the high-gain detection tube core, the medium-low gain detection tube core and the ordinary photodiode tube core on the photoelectric detection chip.

[0021] Fig. 4 is one of the integrated structures of the high-gain detection tube core, the medium-low gain detection tube core and the ordinary photodiode tube core on the photoelectric detection chip.

[0022] Fig. 5 is one of the integrated structures of the high-gain detection tube core, the medium-low gain detection tube core and the ordinary photodiode tube core on the photoelectric detection chip.

[0023] Fig. 6 is one of the integrated structures of high-gain detection die, middle-low gain detection die and common photodiode die on the photoelectric detection chip.

[0024] Wherein, the name corresponding to the reference numeral is: 1-semiconductor laser die, 2-package carrier, 3-collimating lens barrel, 4-collimating lens, 5-receiving lens, 6-reflecting platform, 8-photoelectric detection chip, 10-bracket, 11-detected object, 31-light hole, 8a-high gain detection die, 8b-middle-low gain detection die, 8c-common photodiode die. DETAILED DESCRIPTION

[0025] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application in combination with the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall into the protection scope of the present application.

[0026] The first structure of a laser transceiver device is shown in Fig. 1, which comprises a bracket 10, and a semiconductor laser die 1, a package carrier 2, a collimating lens barrel 3, a collimating lens 4, a receiving lens 5, a reflecting platform 6 and a photoelectric detection chip 8 mounted on the bracket 10; the package carrier 2 is provided with positive and negative electrodes, the semiconductor laser die 1 is a laser diode, and its positive and negative electrodes are connected to the corresponding electrodes of the package carrier 2 respectively; the collimating lens barrel 3 is sleeved outside the semiconductor laser die 1, the collimating lens barrel 3 is provided with a light hole 31 on the barrel wall, the collimating lens 4 is installed at the port of the collimating lens barrel 3 and is opposite to the detected object 11, and the reflecting platform 6 is located on the extension line of the connecting line of the semiconductor laser die 1 and the light hole 31; the photoelectric detection chip 8 is integrated with a high-gain detection die 8a and a common photodiode die 8c, the receiving lens 5 is opposite to the high-gain detection die 8a, and as an option, the axis of the receiving lens 5 passes through the center of the high-gain detection die 8a. The bracket 10 is mainly used for fixing the positions of the above optical components.

[0027] The external modulating signal is inputted by the positive and negative electrodes of the packaging carrier 2, and then is transmitted to the semiconductor laser die 1 through the electrodes of the semiconductor laser die 1, and the collimated semiconductor laser die 1 emits laser carrying the modulating signal; most of the laser is collimated by the collimating lens 4, and then is reflected by the detected object 11, and is collected by the receiving lens 5 and gathered to the high-gain detection die 8a to form an external echo electric signal; due to the characteristics of the semiconductor laser die 1, the emitted laser has a certain divergence, and a small part of the laser is scattered to the reflecting platform 6 through the light transmission hole 31, and is reflected by the reflecting platform 6 and irradiated on the high-gain detection die 8a and the ordinary photodiode die 8c at the same time, and an internal reference electric signal is formed on the high-gain detection die 8a, and a direct current electric signal proportional to the emission power of the laser is formed on the ordinary photodiode die 8c.

[0028] The first structure of the present application integrates the high-gain detection die 8a and the ordinary photodiode die 8c on the photoelectric detection chip 8, and separately packages the semiconductor laser die 1. The laser before collimation is used to form a direct current electric signal and an internal reference electric signal, and the laser after collimation is used to form an external echo electric signal. The direct current electric signal is proportional to the emission power of the laser, and can be used to adjust the emission power of the laser to adapt to different distances and objects to be measured. The internal reference electric signal and the external echo electric signal are used for calculating the distance of the detected object.

[0029] The different distances and colors of the detected object have an influence on the intensity of the reflected laser, that is, the size of the external echo electric signal returned from the detected object is related to the distance and reflectivity of the measured object. For example, the reflectivity of a white object is higher than that of a black object, and when the distance of the black object is measured, the external echo electric signal formed by reflection is small, and at this time, the emission power of the laser needs to be increased to enhance the external echo electric signal so that it can be more easily detected. For another example, when the distance of the same object is measured, the farther the distance, the smaller the external echo electric signal formed by reflection, and at this time, the emission power of the laser also needs to be increased to enhance the external echo electric signal. The present application adjusts the emission power of the laser through the direct current electric signal to adapt to different distances and objects to be measured.

[0030] A second structure of a laser transceiver device is shown in FIG. 2, and the second structure optimizes the integrated structure on the photoelectric detection chip 8 on the basis of the first structure. The photoelectric detection chip 8 further integrates a medium-low gain detection die 8b, and the medium-low gain detection die 8b is located between the high-gain detection die 8a and the ordinary photodiode die 8c.

[0031] The external modulation signal is input through the positive and negative electrodes of the packaging carrier 2, and then transmitted to the semiconductor laser die 1 through the electrodes of the semiconductor laser die 1. The collimated semiconductor laser die 1 emits laser carrying the modulation signal. Most of the laser is collimated by the collimating lens 4, reflected by the detected object 11, collected by the receiving lens 5, and then gathered to the high-gain detection die 8a to form an external echo electric signal. A small part of the laser is scattered to the reflecting platform 6 through the light transmission hole 31, and then irradiated to the medium-low gain detection die 8b and the ordinary photodiode die 8c on the reflecting platform 6. The internal reference electric signal is formed on the medium-low gain detection die 8b, and the direct current electric signal proportional to the emission power of the laser is formed on the ordinary photodiode die 8c.

[0032] The second structure of the application integrates the high-gain detection die 8a, the medium-low gain detection die 8b, and the ordinary photodiode die 8c on the photoelectric detection chip 8. Since the internal reference electric signal and the direct current electric signal are formed by the same laser with the same emission power, in order to adapt to the long-distance or low-reflectivity detected object, it is necessary to increase the emission power of the laser. At this time, the internal reference electric signal will also increase. If the external echo electric signal and the internal reference electric signal use the same gain high-gain detection die 8a, the internal reference electric signal will be too strong to cause the receiving area to be saturated, thereby causing signal distortion and incorrect detection. Therefore, the application adds the medium-low gain detection die 8b as a medium-low gain area to meet the requirement of larger laser emission power.

[0033] In some embodiments, the high-gain detection die 8a is any one of an avalanche photodiode, a single-photon avalanche diode, or a silicon photodiode, and the ordinary photodiode die 8c is an ordinary photodiode.

[0034] In some embodiments, the medium-low gain detection die 8b is an ordinary photodiode, or other photodiodes.

[0035] In some embodiments, the high-gain detection die 8a and the medium-low gain detection die 8b use the same bias driving voltage, and do not need to configure different bias driving voltages to achieve the detection of corresponding signals, which has advantages in system control complexity, processing speed, cost, and volume. In addition, the high-gain detection die 8a and the medium-low gain detection die 8b can also use different driving voltages, but the system complexity is higher than that of the same bias driving voltage.

[0036] In some embodiments, the standard emission power of the semiconductor laser die 1 is set before the transceiver officially measures the distance, that is, the emission power of the laser is set by a direct current signal, and then the emission power is further adjusted according to the signal-to-noise ratio to meet the reflectivity of the current detected object or the required distance. Specifically, the following operations are included: Sa, the semiconductor laser die 1 emits laser with a preset initial emission power, monitors the direct current signal, adjusts the laser emission power until the direct current signal is equal to or greater than the preset value, and records the current laser emission power as the adjusted emission power; Sb, the adjusted emission power is used to emit laser, the signal-to-noise ratio is obtained according to the external echo electric signal and the internal reference electric signal, and the standard emission power is set according to the signal-to-noise ratio. The direct current signal is proportional to the laser emission power, and the laser emission power can be calculated by monitoring the direct current signal, and the external echo electric signal reflected from the detected object is used to adjust the laser emission power, and the laser emission power can be increased when the external echo electric signal is small.

[0037] The ranging method of the laser transceiver of the present application adopts a direct pulse method or a phase pulse method.

[0038] When the direct pulse method is adopted, the time difference is obtained based on the time when the internal reference electric signal is received by the photoelectric detection chip 8 and the time when the external echo electric signal is received by the photoelectric detection chip 8, and then the distance of the detected object 11 is calculated based on the time difference. Specifically, the time point when the internal reference electric signal is received by the photoelectric detection chip 8 is taken as the counting start point, and the time point when the external echo electric signal is received by the photoelectric detection chip 8 is taken as the counting end point, the counting time difference is obtained according to the difference between the counting values of the counting start point and the counting end point, and then the distance of the detected object is obtained by combining the propagation speed of light in the atmosphere and the counting time scale, and the calculation formula is as follows: d = c * (cnt stop -cnt start )*tresolution / 2;

[0039] d is the distance of the detected object, c is the propagation speed of light in the atmosphere, cnt stop is the counting start point, cnt start is the counting end point, and tresolution is the counting time scale. The counting time scale is realized by the counter in the photoelectric detection chip 8, and the counting time scale represents the time represented by the counter each time it is added, for example, the counter represents 1 picosecond each time it is added, and the counting time scale is determined by the hardware circuit of the counter and is a known constant.

[0040] When the phase pulse method is adopted, the phase difference is obtained based on the initial phase of the internal reference electric signal and the terminal phase of the external echo electric signal, and the distance of the detected object 11 is calculated based on the phase difference. Specifically, the photoelectric detection chip 8 receives and detects the initial phase of the internal reference electric signal and the terminal phase of the external echo electric signal, obtains the phase difference between the two, and then obtains the distance of the detected object by combining the propagation speed of light in the atmosphere and the wavelength of the modulation signal. The calculation formula is as follows: d = (c / 2) x (Φ / 2πf) = (λ / 2) x (Φ / 2π);

[0041] d is the distance of the detected object, c is the propagation speed of light in the atmosphere, Φ is the phase difference, and λ is the wavelength of the modulation signal. The phase difference Φ is obtained by subtracting the initial phase pulse position from the terminal phase pulse position.

[0042] As shown in FIGS. 3-6, the first and second structural examples of the present application can integrate the high-gain detection die 8a, the medium-low-gain detection die 8b, and the ordinary photodiode die 8c in different regions of the photoelectric detection chip 8 with different sizes according to actual application needs. The integration positions of the high-gain detection die 8a, the medium-low-gain detection die 8b, and the ordinary photodiode die 8c are not limited to those described in FIGS. 3-6. The integration positions can be adjusted according to the positions of the receiving lens 5 and the reflecting platform 6 to adapt to different optical structures and detection ranges, reduce the overall volume, and improve the system performance. For example, for long-distance ranging, the high-gain detection die 8a can be increased and the medium-low-gain detection die 8b can be reduced to receive more external reflected light, and the laser emission power can be increased to avoid saturation of the medium-low-gain detection die 8b.

[0043] As a preferred embodiment, the semiconductor laser die 1 can also be directly placed on a PCB (printed circuit board), and the PCB directly replaces the packaging carrier 2, eliminating the packaging carrier 2 and the corresponding soldering. The semiconductor laser die lead is directly connected to the PCB, and the PCB is fixed on the bracket 10. The semiconductor laser die 1 does not need to be individually packaged, which reduces the complexity of the packaging structure while greatly reducing the volume and corresponding cost.

[0044] Finally, it should be noted that: the above embodiments are merely the preferred embodiments of the present application to illustrate the technical solutions of the present application, rather than limit, of course, is not to limit the scope of the patent of the present application; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still be modified to the technical solutions recorded in the foregoing embodiments, or part or all of the technical features are replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application; that is to say, but whatever is made in the main design idea and spirit of the present application has no substantial significance of the change or polish, the technical problem solved is still consistent with the present application, and should be included in the protection scope of the present application; in addition, the technical solutions of the present application are directly or indirectly applied to other related technical fields, which are also included in the patent protection scope of the present application.

Claims

1. A laser transceiver device, comprising: The application relates to a semiconductor laser package, which comprises a support (10), a semiconductor laser die (1), a package carrier (2), a collimating cylinder (3), a collimating lens (4), a receiving lens (5), a reflecting platform (6) and a photoelectric detection chip (8) which are mounted on the support (10); the package carrier (2) is provided with positive and negative electrodes, the positive and negative electrodes of the semiconductor laser die (1) are connected to the corresponding electrodes of the package carrier (2) respectively; the collimating cylinder (3) is sleeved on the semiconductor laser die (1), the collimating cylinder (3) is provided with a light transmission hole (31) on the cylinder wall, the collimating lens (4) is mounted on the port of the collimating cylinder (3) and is opposite to a detected object (11), the reflecting platform (6) is located on the extension line of the semiconductor laser die (1) and the light transmission hole (31); the photoelectric detection chip (8) is integrated with a high-gain detection die (8a) and a common photoelectric diode die (8c), and the receiving lens (5) is opposite to the high-gain detection die (8a).

2. A laser transceiver as claimed in claim 1, wherein An external modulation signal is input by the positive and negative electrodes of the package carrier (2), is transmitted to the semiconductor laser die (1) through the electrodes of the semiconductor laser die (1), is emitted by the collimated semiconductor laser die (1), and carries the modulation signal; most of the laser is collimated by the collimating lens (4), is reflected by the detected object (11), is collected by the receiving lens (5) and is converged to the high-gain detection die (8a) to form an external echo electric signal, a small part of the laser is scattered to the reflecting platform (6) through the light transmission hole (31), is reflected by the reflecting platform (6) and is irradiated on the high-gain detection die (8a) and the common photoelectric diode die (8c) at the same time, an internal reference electric signal is formed on the high-gain detection die (8a), and a direct current electric signal proportional to the emission power of the laser is formed on the common photoelectric diode die (8c).

3. A laser transceiver as claimed in claim 1, wherein The high-gain detection die (8a) is any one of an avalanche photodiode, a single-photon avalanche diode or a silicon photodiode, and the common photoelectric diode die (8c) is a common photoelectric diode.

4. A laser transceiver as claimed in claim 1, wherein The photoelectric detection chip (8) is further integrated with a medium-low gain detection die (8b), and the medium-low gain detection die (8b) is located between the high-gain detection die (8a) and the common photoelectric diode die (8c).

5. A laser transceiver as claimed in claim 4, wherein The external modulation signal is input through the positive and negative electrodes of the packaging carrier (2), and then transmitted to the semiconductor laser die (1) through the electrodes of the semiconductor laser die (1), and the collimated semiconductor laser die (1) emits laser carrying the modulation signal; most of the laser is collimated through the collimating lens (4), and then reflected by the detected object (11), collected by the receiving lens (5) and converged to the high-gain detection die (8a) to form an external echo electric signal, and a small part of the laser is scattered to the reflecting platform (6) through the light transmission hole (31), and then reflected by the reflecting platform (6) and irradiated on the medium-low gain detection die (8b) and the ordinary photodiode die (8c), forming an internal reference electric signal on the medium-low gain detection die (8b), and a direct current electric signal proportional to the emission power of the laser on the ordinary photodiode die (8c).

6. A laser transceiver as claimed in claim 4, wherein The medium-low gain detection die (8b) is an ordinary photodiode.

7. A laser transceiver as claimed in claim 4, wherein The high-gain detection die (8a) and the medium-low gain detection die (8b) use the same bias driving voltage.

8. A laser transceiver as claimed in claim 1, wherein, Before the transceiver device formally measures the distance, the standard emission power of the laser emitted by the semiconductor laser die (1) is set, and the method comprises the following steps: Sa, the semiconductor laser die (1) emits laser with a preset initial emission power, and the direct current signal is monitored, and the laser emission power is adjusted until the direct current signal is equal to or greater than the preset value, and the current laser emission power is recorded as the adjusted emission power; Sb, the laser is emitted with the adjusted emission power, the signal-to-noise ratio is obtained according to the external echo electric signal and the internal reference electric signal, and the standard emission power is set according to the signal-to-noise ratio.

9. A laser transceiver as claimed in claim 1, wherein, When the distance measuring method of the transceiver device adopts the direct pulse method, the time difference between the time when the internal reference electric signal is received by the photoelectric detection chip (8) and the time when the external echo electric signal is received by the photoelectric detection chip (8) is obtained, and then the distance of the detected object (11) is calculated through the time difference.

10. A laser transceiver as claimed in claim 1, wherein, When the distance measuring method of the transceiver device adopts the phase pulse method, the phase difference between the initial phase of the internal reference electric signal and the terminal phase of the external echo electric signal is obtained, and then the distance of the detected object (11) is calculated through the phase difference.

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