Mini light adjustable receiver

Abstract

The invention discloses a mini light adjustable receiver which comprises a TO pedestal, a TO tube cap, a filter and an avalanche photodiode. The TO tube cap is fixed on the TO pedestal, the end, far from the TO pedestal, of the TO tube cap includes a window, the avalanche photodiode and filter are packaged in the TO tube cap sequentially, and the avalanche photodiode is arranged on the TO pedestal; and a focusing lens is arranged between the reception surface of the avalanche photodiode and the filter. Via the structure, the focusing lens is arranged between the reception surface of the avalanche photodiode and the filter to provide the coupling efficiency of the avalanche photodiode, after addition of the focusing lens, light of relatively large light spots and low divergence angle is allowed to enter, the walk-off effect is reduced much, the bandwidth of light received by the avalanche photodiode is not much deviated from a theoretical value, the coupling efficiency in the central wavelength is higher, the sensitivity is improved, and crosstalk among channels is reduced.

Description

technical field [0001] The invention relates to the field of high-speed optical communication, in particular to a miniaturized optical adjustable receiver. Background technique [0002] The active area of ​​the APD used in high-speed optical communication is very small, and the higher the rate, the smaller the area. This requires that the spot area focused on the active area of ​​the APD is also relatively small. At present, the tunable optical receiver (TRx) developed by our company for the TWDM-PON system is designed to directly enter the APD after the focused beam passes through the filter. ;A fatal problem of this design is that the focused beam with a relatively large divergence angle has a large walk-off angle when passing through the filter, and the effective aperture of the APD is not enough to receive light from all angles, resulting in the light received by the APD. The transmission spectrum bandwidth is wider than the transmission spectrum width of the filter und...

AI Technical Summary

Problems solved by technology

This requires that the spot area focused on the active area of ​​the APD is also relatively small. At present, the tunable optical receiver (TRx) developed by our company for the TWDM-PON system is designed to directly enter the APD after the focused beam passes through the filter. ;A fatal problem of this design is that the focused beam with a relatively large divergence angle has a large walk-off angle when passing through the filter, and the effective aperture of the APD is not enough to receive light from all angles, resulting in the light received by the APD. The transmission spectrum bandwidth is wider than the transmission spectrum width of the filter under normal circumstances, and it will cause a decrease in the coupling efficiency at the peak; the decrease in the coupling efficiency will lead to a decrease in the sensitivity of the photoelectric receiver, and the widening of the bandwidth will cause the adjacent channel The crosstalk increases, the bit error rate increases, and the system cost increases

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