Simultaneous interference exposure of different-period DBRs for intra-board WDM optical interconnection

Integration of different-period distributed Bragg reflectors (DBRs) is required in constructing an intra-board optical interconnection device with wavelength division multiplexing (WDM). Interference exposure method with cylindrical Lloyd mirror optics and mask aligner was discussed for integrating those DBRs simultaneously. DBRs were designed to give coupling efficiency higher than 80% with coupling length of 0.6 mm and crosstalk noise less than -10 dB with 3 nm wavelength separation for optical interconnection using eight wavelengths around 850 nm. Interference exposure system was developed and integration of eight DBRs by two times exposure was demonstrated.