Design Of Automatical On-wafer Testing System For V-cavity Lasers

In the course of the rapid development of optical communication technology,light source of communication is an indispensable member of optical fiber network.The optical chip is the core of the light source,and the tunable laser is an important member of the optical chip.The tunable laser with high quality and low price is the common goal of the research workers.The tunable semiconductor laser with V-coupled cavity that our laboratory has researched independently has the above characteristics,and it shows promising outlook.In order to solve the manual monotonous chip testing work and improve the efficiency of mass production,this paper has proposed the automatical on-wafer testing system,aimed at the test of this unpackaged tunable semiconductor laser with V-coupled cavity.This system takes the block of wafer as the test unit,and a test scheme is designed.The hardware design of the mechanical part of the system is completed by SolidWorks,including probe arm,chip fixture,optical fiber fixture,and so on.The appropriate test and control instruments are selected to provide hardware conditions for the system.Lab VIEW is used to complete the software design of the system.Using the producer-consumer model and the implementation of the queue state machine,the function module can be added and deleted arbitrarily without modifying the whole program.Completed function mainly includes automatical powering on,automatical coupling of light,chip performance test(I-L-V curve,wavelength,SMSR),chip quality evaluation,generating a data record table,and so on,which realizes the automation of the system.Different from the on-wafer testing of surface emitting lasers,the design focus of this paper are automatical powering on and automatical coupling of light.The feasible analysis of luminous power and coupling direction provides a reliable basic on the design of the system.After determining the new test standard and analyzing the repeated I-V test,now the system has been used in production line,and has liberated the manual operation.The test rate is increased from 7 minutes/laser to less than 3 minutes/laser,which greatly improves the test efficiency.