Enhanced Coupling Efficiency of Optical Fiber to Green Light Waveguide by Optical Phased Array

The coupling efficiency between optical fiber and blue-green light waveguide is pretty low since the limited size of sub-micrometer waveguides fabricated for the blue-green light waveguides, which largely limits the applications of photonic circuits at blue-green light wavelengths. Here we propose the mode field spot of wedge-shaped optical fiber lens is applied to couple the laser light into an optical phased array (OPA) by multiple waveguide channels. The numerical results show that compared to the optical coupling of green light waveguide by single-mode optical fiber, the coupling efficiency can be improved by 100% with 12 channels of OPA is coupled by a wedge-shaped optical fiber lens. This study may solve the coupling problems of blue-green light on photonic chips and have the great potential applications of photonic circuits at blue-green wavelengths.