Design of a DFB / DBR diode laser module including spectral multiplexing based on VBGs

We present the concept of a modular fiber coupled building block based on chirped DFB or DBR diode laser bars and a Dense Wavelength Division Multiplexer including Volume Bragg Gratings. The minimum channel spacing is 1.5 nm. Multiplexing efficiencies of 97% have been demonstrated in a pre-testing of the multiplexing unit with single mode, frequency stabilized diode laser radiation. For the presented building block with a beam parameter product of 2.2 mm mrad per emitter, the expected multiplexing efficiency is between 90% and 95% for a channel spacing of 1.5 nm, assuming a spectral width between 100 pm and 400 pm per channel.