Bragg gratings for 1.55-μm wavelength fabricated on semiconductor material by grating-period doubling using a phase mask

A 240-nm-period grating has been fabricated in photoresist on semiconductor material by doubling of the phase-mask grating period. A standard mask aligner retrofitted with a UV laser was used for lithography. The phase mask was optimized via numerical simulation of the distribution of optical power in the photoresist.<
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