Efficient and mode selective spatial mode multiplexer based on Multi-Plane Light Conversion

G. Labroille¹, B. Denolle¹, P. Jian¹, P. Genevaux², N. Treps^1,3, J.-F. Morizur¹

¹ CAILabs, ² Alcatel-Lucent Bell Labs, ³ Laboratoire Kastler Brossel

Optics Express 22, 15599 (2014).

Abstract: We designed and built a new type of spatial mode multiplexer, based on Multi-Plane Light Conversion (MPLC), with very low intrinsic loss and high mode selectivity. In this first demonstration we show that a typical 3-mode multiplexer achieves a mode selectivity better than −23 dB and a total insertion efficiency of −4.1 dB (optical coating improvements could increase efficiency to −2.4 dB), across the full C-band. Moreover this multiplexer is able to perform any mode conversion, and we demonstrate its performance for the first 6 eigenmodes of a few-mode fiber: LP₀₁, LP_11a, LP_11b, LP₀₂, LP_21a and LP_21b.