Abstract

3×3 couplers are increasingly being used in passive stabilization schemes for Mach-Zehnder and Sagnac effect interferometers.¹ The coupling coefficients of the 3×3 couplers, K_ij, play a critical role in the feedback circuits that form the backbone of the stabilization schemes.² In practical interferometric schemes, stabilization would be easier to achieve if the electronic tuning in the feedback system were assisted by a coupler with a variable splitting ratio. The splitting ratios in the coupler would have to be insensitive to changes in the polarization state of the input light.

© 1991 Optical Society of America