Volume holographic wavelength filters based on transmissive-writing and orthogonal-readout scheme

Owing to the high Bragg selectivity and capacity of multiple recording, volume holography has been widely investigated for devices such as wavelength filters in wavelength-division multiplexing fiber communication systems in recent years. Transmission-Writing and Orthogonal-Readout scheme (TWOR) has been proposed for making wavelength filters in holographic media. In this paper, experiments on wavelength selectivity of volume gratings with TWOR scheme are successfully conducted for the first time to our knowledge. Readout by wavelength-tuning showed that a 3-dB bandwidth of 0.5nm was achieved. The experimental results agreed well with the expectation of 2-D coupled-wave theory, and verified the feasibility of TWOR scheme.