Design Of Automatic Calibration System For V-Cavity Tunable SFP Module

With the rapid deployment of 5g commercialization,the market is eager for a large number of low-cost tunable optical modules.Calibration,as a process which consumes a lot of manpower,time and repeatability in the module production stage,is an important step to achieve the final mass production.In this article,2.5G SFP is tested in all directions,and the flow,hardware system and upper computer program of the automatic calibration system are designed.The calibration principle is for v-cavity tunable laser,and for the optical modules with different speed and packaging mode,the calibration parameters can be adjusted slightly,and the main contents are as follows:Firstly,the hardware part of the automatic calibration system is designed,and a set of calibration system and optical path controlled by the upper computer is built.Through the high temperature test of the module,the restriction relationship between the cavity current and Tec temperature is obtained,and the threshold value of each parameter in the calibration of the module is determined.According to the discrete tuning principle of laser vernier effect and the influence of current thermal effect on wavelength,two different calibration methods are proposed:multi segment splicing method and continuous scanning method.The two methods have advantages and disadvantages.Finally,more than 16 continuous channels with 100GHz interval can be calibrated.The channel SMSR is greater than 36dB,the eye map is opened,and the sensitivity reaches more than-17dbm after 25km transmission.The calibration time is about 15 minutes,less than 30 minutes of manual calibration.Finally,the inspiration of quasi continuous tuning of automatic calibration system is discussed,and the design idea of quasi continuous tuning algorithm is improved.The upper computer of quasi continuous tuning and scanning is designed.The wavelength quasi continuous tuning of about 10nm is realized by using the auto calibration module.The scanning speed is up to 200 points/s,and the wavelength error is not more than 10pm.