DESIGN AND APPLICATION OF VERY LOW-LOSS ABRUPT BENDS IN OPTICAL WAVE-GUIDES

A new low-loss abrupt bend structure of the microprism type is propose d. This new bend uses a microprism to compensate for the phase differe nce of the phase front before and after the bend corner, so the entire phase front of the eigenmode is tilted properly, resulting in a very low-loss characteristic. Simulated results show that a normalized tran smitted power of greater than 95% is achieved for a bend angle of 10 d egrees. Moreover, a phase compensation rule and its corrections are pr esented to determine the optimal prism parameters. Application example s of the microprism to design a very low-loss large-angle Z-bend and t wo cascaded Z-bends are also shown.