All-fiber polarizer based on a null taper coupler

Abstract

An entirely new type of single-mode all-fiber polarizer is reported. The polarizer is based on a narrow circularly fused null taper coupler, which was twisted through 45 degrees after being made. The polarizing effect is due to the excitation of hybrid second modes in the coupler waist. An extinction ratio of 15 dB and an insertion loss of 0.2 dB have been obtained, with scope for further improvement.

The photonic lantern

“…It is of course possible to simultaneously taper more than one fibre in this way. Indeed, the most technologically-important tapered fibre device is the four-port fused coupler, a fibre-optic beamsplitter made by tapering a parallel pair of fibres [81][82][83][84][85][86][87]. In that case, not only do the fibres reduce in size along the transitions but they also fuse together to form a single monolithic structure.…”

Enhance performance of acoustic-optical tunable filters by using spectral servo

“…In above equation, 2 2 sin(κL) 2 > 0, 1 + s 2 2 sin(κL) 2 s 2 1 + 2s 2 sin(κL)s 1 cos(φ) ≥ 1 + s 2 2 sin(κL) 2 s 2 1 − 2s 2 sin(κL)s 1 > 0.…”

Optical force between two coupled identical parallel optical nanofibers

“…Optical devices based on coupled tapered thin fibers have been produced and studied [19][20][21]. Recently, miniaturized optical devices composed of coupled twisted and knotted optical nanofibers have been fabricated [20].…”