Drivers for Vertical Cavity Surface Emitting Lasers

Abstract

The invention provides a driver of a vertical cavity surface emitting laser. The driver comprises a signal preprocessor, a modulating pulse generation circuit, a rising edge pre-emphasis circuit and a falling edge pre-emphasis circuit. The signal preprocessor outputs three sets of differential voltage signals which are connected with the modulating pulse generation circuit, the rising edge pre-emphasis circuit and the falling edge pre-emphasis circuit respectively and correspondingly; the modulating pulse generation circuit converts the differential synchronous data voltage signals into initial modulating current; the falling edge pre-emphasis circuit converts the differential falling edge voltage signals into falling edge pre-emphasis current; the rising edge pre-emphasis circuit converts the differential rising edge voltage signals into rising edge pre-emphasis current; the initial modulating current, the falling edge pre-emphasis current and the rising edge pre-emphasis current are directly coupled into final output current to drive the vertical cavity surface emitting laser to work. According to the driver, emphasis current pulses capable of being modulated are independently generated at the falling edge and the rising edge of input signals, attenuation of optical waveforms of the laser under high frequency is fully restrained, and the driver is suitable for high-speed bar-to-bar optical interconnected systems.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and in particular relates to a driver for driving a vertical cavity surface emitting laser. Background technique [0002] In the high-speed low-power optical interconnection system, since the vertical cavity surface emitting laser has a small threshold current and can be made into a two-dimensional array, it is very suitable for multi-channel parallel transmission systems. For this reason, vertical cavity surface emitting lasers are the core components of optical interconnection systems. However, due to the existence of parasitic capacitance and parasitic inductance in the assembly system, as the data transmission rate increases, serious light wave attenuation will occur. The waveform of the light wave is directly related to the instantaneous power of the laser, and the instantaneous power of the laser is determined by the current intensity driving the laser. Therefore, for the prob...

AI Technical Summary

Problems solved by technology

Although this solution can suppress the attenuation of the optical waveform of the vertical cavity surface emitting laser to a certain extent, because the finite impulse response filter in the traditional technology is a linear system, the response of the vertical cavity surface emitting laser is nonlinear, that is, the rising edge and the emphasis signal required by the falling edge are asymmetrical, so this scheme cannot fully suppress the attenuation of the optical waveform in the optical interconnection system, and when the extinction ratio is set large enough to obtain a sufficient signal-to-noise ratio, this problem become particularly serious

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