JPWO2019160696A5 - - Google Patents

Claims (23)

A primary avalanche photodiode (APD) capable of receiving and detecting a multi-return optical signal when activated by a first bias signal, said multi-return optical signal containing two or more optical pulses. , Primary APD,
A secondary APD capable of operating to receive and detect the multi-return optical signal when activated by a second bias signal.
A delay circuit that generates the second bias signal by adding a delay to the first bias signal, and
It is possible to operate to combine the first output generated by the primary APD based on the detection of the multiple return optical signal and the second output generated by the secondary APD based on the detection of the multiple return optical signal. With a combiner,
When the primary APD is saturated when the first pulse of the multi-return optical signal is detected, the secondary APD decodes the second pulse of the multi-return optical signal following the first pulse. .. The system of claim 1, further comprising a distance gate control that can operate to control the delay circuit. The system of claim 1, wherein the secondary APD is attenuated relative to the primary APD. Claimed, the secondary APD is arranged on an optical surface different from the primary APD so that the secondary APD receives the multi-return optical signal having a light intensity lower than that of the primary APD. The system according to 3. The first aspect of claim 1, further comprising a current amplifier, wherein the second output of the secondary APD comprises an output current and the current amplifier can operate to amplify the output power of the secondary APD. System. Further comprising a gain controller, the first output of the primary APD comprises an output current, the gain controller via an inverting gain ratio control based on the output current of the primary APD and the output current of the secondary APD. 5. The system of claim 5, which is capable of operating to control the current amplifier. The system of claim 1, further comprising a diversity-enhanced photodetector coupled to the output of the combiner and capable of operating to generate a detected multi-return signal. 1. system. The system of claim 1, comprising two or more primary APDs and two or more secondary APDs. Further a controller capable of operating to select one of the two or more primary APDs and one of the two or more secondary APDs to detect the multiple return optical signal. The system according to claim 9. The system of claim 1, wherein the combiner performs MIMO processing using maximum gain ratio coupling. A step of receiving a multi-return optical signal in a primary APD, wherein the multi-return optical signal comprises a series of pulses that saturate the primary APD and generate a detection blind spot.
A step of receiving a multiple return optical signal in the secondary APD, wherein the secondary APD operates in an overlapping manner with respect to the primary APD.
The step of detecting the pulse of the multiple return optical signal hidden in the detection blind spot of the primary APD by the secondary APD, and the step of detecting the pulse.
Including the method. There is optical separation between the secondary APD and the primary APD, and the optical intensity of the multi-return optical signal received by the secondary APD is higher than the optical intensity of the multi-return optical signal received by the primary APD. The method of claim 12, also attenuated. 13. When the primary APD is saturated by the multi-return optical signal, the secondary APD avoids saturation due to attenuation of the light intensity of the multi-return optical signal received by the secondary APD, claim 13. The method described in. The detection of the multi-return optical signal in the primary APD is activated by the first bias signal, the detection of the multi-return optical signal in the secondary APD is activated by the second bias signal, and the second bias signal is 12. The method of claim 12, wherein the delay step delays the first bias signal. 15. The method of claim 15, wherein the delay step is part of the pulse width of the multi-return optical signal. Two or more primary avalanche photodiodes (APDs), each capable of operating to detect a multi-return optical signal when activated by a first bias signal, the two multi-return optical signals. Two or more primary APDs, including the above pulses,
Two or more secondary APDs, each capable of operating to detect the multiple return light signal when activated by a second bias signal, each of the two or more secondary APDs. Two or more secondary APDs that can operate in an overlapping manner with each of the two or more primary APDs to detect the multiple return optical signal.
A controller capable of operating to select one of the two or more secondary APDs and one of the two or more primary APDs for the detection of multiple return optical signals.
A system equipped with. 17. The system of claim 17, wherein the basis for selection of primary and secondary APDs is predefined. 17. The system of claim 17, wherein the primary and secondary APDs are dynamically selected based on the signal processing information of the multi-return optical signal. 19. The system of claim 19, wherein the dynamic selection modifies the firing order of the primary APD. 19. The system of claim 19, wherein the dynamic selection adjusts the second bias signal relative to the first bias signal. 19. The system of claim 19, wherein the dynamic selection is based on their respective positions on the focal planes of the primary and secondary APDs. 17. Claim 17, wherein the selected secondary APD is placed away from the principal optical focal plane of the selected primary APD to attenuate the selected secondary APD relative to the selected primary APD. System.