Analysis of the chirped super Moire gratings based on acousto-optical superlattices

There are multiple passbands in a chirped Bragg grating based on acousto-op tic superlattice. The structure can be regarded as an acousto-induced super Moire grating (AI-SMG). The analysis shows that the passbands of the AI-SM G are produced by several pairs of neighboring chirped gratings. With suita ble structure parameters selected, the passbands can be non-larenzian-shape , narrow flat-top, with ripple less than 0.5dB and steep slope. The devices can be used as tunable narrow-band multichannel transmission filters. This analysis is useful for the designs and applications of the devices.