Research On Detector Array Chip With High Density Muti-core Fiber Matching

With the rapid development of social informatization,photodetectors have played an increasingly important role in modern optical fiber communication systems.During the communication process,the explosive growth of information flow,especially with the development of emerging technologies such as 5G,cloud computing,and the Internet of Things,has led to increasing demands for communication system bandwidth,and the capacity expansion of optical fiber transmission channels has become an important requirement.Multi-core fiber,as an important means of expanding communication channels,has also received widespread attention.However,the development of multi-core fiber fan-in/fan-out devices faces challenges such as high cost,large volume,installation,and maintenance.Therefore,the design of detector array chips that match multi-core fiber has become particularly important.It can realize the efficient use and application of multi-core fiber,reduce the use of optical components,and lower system costs.In this paper,we mainly researched the design of an indium gallium arsenide/indium phosphide(In Ga As/In P)material detector array chip that matches high-density multi-core fiber.The chip integrates a grating coupler,tapered waveguide,and photodetector into a single chip and has been successfully fabricated,packaged,and tested.We designed detector array chips that match multi-core fibers with 4,7,and 19 cores,respectively,and integrated the grating coupler array,taper waveguide,and photodetector array into a single chip.After fabricating and packaging the detector array chips,we built a system to test the optoelectronic performance parameters of the photodetectors in the chip and analyzed the test results.The results showed that the dark current increased with the rise of reverse bias voltage.Under a reverse bias voltage of 0-4V,the detector output dark current at the p A-n A level.At a frequency of 100 k Hz,the minimum equivalent junction capacitance of the photodetector was 6p F.Under the environment of 4V reverse bias voltage and 1550 nm wavelength light,considering the loss of the fiber-to-grating coupler and the loss of the optical signal from the grating coupler to the photodetector through the tapered waveguide,the maximum spectral responsivity that the photodetector can achieve is 4.5m A/W.The research results of this paper show that the detector array chip designed for high-density multi-core fiber matching has good performance.Meanwhile,the optoelectronic performance parameter test system built in this study can also provide reference for relevant research.