3 x 3 single-mode star coupler made from 2 x 2 couplers.
An optical network made from two 3-dB and one 1.76-dB 2 x 2 single-mode couplers can perform as a 3 x 3 star coupler. One version is particularly suitable for polarization-preserving components and requires adjustment of the phase in one arm; it can also perform the three-point discrete Fourier transform by suitable adjustment of other phases. Experimental verification of the principle is presented.
Marhic
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Chang
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