Spectral separation of femtosecond pulses using optical coupler with fiber grating

We have developed spectral separation devices for optical coding, which is based on an optical coupler structure with fiber gratings. In the computer simulation, we confirmed that this device could extract <1 nm bandwidth light with 80% efficiency. We fabricated the spectral separation devices using single mode fibers. These devices successfully extracted a narrow spectral light of 0.3 nm bandwidth with 37% efficiency from femtosecond pulses. We also fabricated 2 channel spectral separation devices, which could extract the light at the each grating channel.