Temperature compensation circuit for laser drive

Abstract

The invention discloses a temperature compensation circuit for a laser drive, comprising a positive temperature coefficient current generation module, a zero temperature coefficient current generation module and a temperature compensation proportion control module, wherein the output ends of the positive temperature coefficient current generation module and the zero temperature coefficient current generation module are respectively connected with the input end of the temperature compensation proportion control module; the positive temperature coefficient current generation module can be used for generating positive temperature coefficient current increasing with the temperature rise so as to determine a slope factor for temperature compensation; the zero temperature coefficient current generation module can be used for generating zero temperature coefficient current irrelevant with the temperature so as to determine the initial temperature of the temperature compensation; and the temperature compensation proportion control module can be used for sampling the difference between the positive temperature coefficient current and the zero temperature coefficient current and overlappingthe difference with the external input current for controlling compensation current to determine the compensation current and further control the proportion of the temperature compensation, The temperature compensation circuit can be used for flexibly adjusting the compensation proportion of a laser and stabilizing the extinction ratio, adapts to the temperature characteristics of different lasers, and has strong generality.

Description

technical field [0001] The invention relates to a temperature compensation circuit, in particular to a temperature compensation circuit applied to a laser driver. Background technique [0002] In an optical communication system, a laser driver (LDD, Laser Diode Driver) and a laser are important components of a transmitter. The laser driver provides the required driving current for the laser. For the characteristics of the threshold current of the laser, the driving current includes the modulation current and the bias current. The modulation current is the high-speed digital signal transmitted, and the bias current is mainly used to turn on the threshold of the laser. Xi. The performance parameters of the laser will change with the temperature, figure 1 The optical power-current curve of the laser diode is shown. As the temperature increases, the threshold current of the laser diode will drift greatly, and the electro-optical conversion efficiency will decrease accordingly....

AI Technical Summary

Problems solved by technology

However, the temperature compensation circuits currently used in laser drivers generally lack flexibility, and the temperature compensation provided is relatively fixed. It is difficult to flexibly adjust the compensation ratio required by the laser and maintain the stability of the extinction ratio of the laser in the full temperature range, and it is difficult to adapt to different conditions. Laser temperature characteristics, poor versatility

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