Optical transmitter and optical signal generating method

Abstract

The invention discloses an optical transmitter and an optical signal generating method, which belong to the field of optical communication. The optical transmitter comprises a first frequency mixer, a second frequency mixer and a modulator; or the optical transmitter comprises a frequency mixer and the modulator. The method comprises the following steps: dividing the data to be transmitted into two paths which are mixed with two paths of clock signals respectively to generate two paths of return-to-zero bipolar signals; and respectively modulating the bipolar signals to generate a CSRZ-DQPSK optical signal. Or the method comprises the following steps: receiving the data to be transmitted and a sine clock signal, adjusting the phase of the sine clock signal to synchronize the phase of the sine clock signal and the data to be transmitted, and carrying out the frequency mixing to generate a Manchester code; and modulating the Manchester code to the optical signal to generate a Manchester optical signal. The method carries out the frequency mixing of the data to be transmitted and the clock signal and drives the modulator through the signal after frequency mixing to generate the CSRZ-DQPSK optical signal or the Manchester optical signal, thereby reducing the cost of the optical transmitter.

Description

technical field [0001] The invention relates to the field of optical communication, in particular to an optical transmitter and a method for generating an optical signal. Background technique [0002] With the increase of communication capacity, especially the popularity of high-speed Ethernet and the development of multimedia services, people have put forward higher requirements for the existing optical fiber communication system. Long-distance, large-capacity wavelength division multiplexing (WDM, Wavelength Division Multiplexing ) system is becoming a research and commercial hotspot. At present, the 40Gb / s system has already started commercial use, and the ultra-high-speed transmission systems of 100Gb / s and 160Gb / s are receiving widespread attention in the industry. As the data rate increases, the performance of traditional transmission systems using amplitude modulation formats such as NRZ (Non Return-to-Zero) and Return-to-Zero (RZ, Return-to-Zero) is greatly affected...

AI Technical Summary

Problems solved by technology

[0005] The transmitter uses two modulators to generate CSRZ optical pulses and DQPSK signals respectively, that is, two-level modulation is required, so the cost of the transmitter is high, the volume is large, and it is not easy to integrate

At the same time, the transmitter uses discrete optical devices, and the driving signals of the two modulators need to be strictly adjusted to achieve synchronization, which increases the insertion loss of the entire transmitter

[0006] In addition, the traditional Manchester pattern is realized through the XOR operation between the clock signal and the data signal (using an XOR gate), but the XOR gate is an active device and needs to be driven by an external voltage, resulting in a relatively high cost of the transmitter. high

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