Low bending loss waveguide opens the avenue to downsizing of 3-D photonic integrated circuits

(Science China Press) Femtosecond lasers have been used for inscribing three-dimensional optical waveguides for a broad spectrum of applications. Currently, the difficulty in inducing large refractive index changes smoothly distributed in the laser irradiated regions is the major obstacle for producing compact photonic integrated circuit. Now researchers in Shanghai provide a solution to suppress the bend loss of the waveguide by sandwiching the waveguide between a pair of walls formed by intern...