Design and simulation of asymmetric Y-junction beam splitter with controllable splitting based on adjusted air-hole defect

Abstract

We report a construction of a new asymmetric Y-junction beam splitter with a controllable splitting ratio and simulate this splitter. The splitter is based on InP, has the area 65.0 µm2 and operates at the light wavelengths 1.48 and 1.55 µm. Under condition of no air-hole defect, the splitting ratio for the output ports 1 and 2 is equal to 92/8 at the both wavelengths. To control the splitting ratio, air-hole defects with different (diamond, square and cylinder) shapes are introduced at the junction between the two output ports. Our simulations confirm that the splitting ratio of the beam splitter can be efficiently controlled by changing the size and the shape of the air-hole defect. The maximal splitting ratios at our operating wavelengths are equal to 10/90 and 14/86 and the appropriate average insertion losses amount to 0.36 and 0.31 dB for all of defect shapes.