Study On Acousto-optic Tunable Filter

Tunable Wavelength Filter is a required component in Wavelength Division Multiplexing (WDM) System. Integrated Acousto-optic tunable filter has the characteristics of easily tuning and wide tunable range, besides, its filtering bandwidth and insert wastage can meet the needs of system very well. What's more, integrated optical filter has the function of Multi-state WDM Switch that was not occupied by other filters. So, Integrated Acousto-optic Tunable Filter has become the most appropriate wavelength filter in WDM system. But factually used AOTF in business requires that the apparatus is not polarization relied, and has low sidelobes. Besides, it must have a very narrow filtering bandwidth rigidly. Although the developed apparatus has reached a relatively high level in some index even in the world, it can't be used in business. So further researches must be carried out. What the thesis contents is the result of these researches. In the first chapter of the thesis, we researched on the TE/TM mode splitter, introduced the basic principle of the directional coupler typed mode splitter, and made factual apparatus which help us solve the problem of AOTF's relying on polarization of incident light; In the second chapter, we substituted quasi-collinear type of acousto-optic interaction for the forgoing collinear one and then suppress sidelobes effectively. The work has been done successfully; In the following chapter, we introduced reflector technology and method to connect single-grade AOTF. The achievement effectively help us solve the problem of too big geometry brought by traditional connective technology; At last, we made use of the high sensitivity of AOTF's characteristic stability due to the change of outer temperature, and successfully developed Acousto-optic Tunable Filter based temperature sensor and Acousto-optic Tunable Filter based spectrometer.