Integrated-optic acoustically tunable reflection filter

Area of Science:

• Photonics
• Acousto-Optics
• Integrated Optics

Background:

• Acousto-optic filters are crucial for wavelength selection in optical systems.
• Achieving high sidelobe suppression and narrow bandwidth in single-stage acousto-optic filters is challenging.
• Existing methods like cascaded filters are complex and difficult to fabricate.

Purpose of the Study:

• To demonstrate a novel two-stage, integrated-optic, acoustically tunable filter.
• To improve sidelobe suppression and reduce filter bandwidth compared to single-stage devices.
• To offer a simpler fabrication alternative to cascaded acousto-optic filters.

Main Methods:

• An integrated-optic acousto-optic filter was designed.
• A double-pass configuration was implemented using an integral mirror to reflect light back through the filter.
• The performance of the double-pass filter was evaluated for sidelobe suppression and bandwidth.

Main Results:

• The double-pass configuration achieved sidelobe suppression of approximately -20 dB.
• A 72% reduction in filter bandwidth was observed, reaching less than 0.9 nm at 1.52 microm.
• The performance was comparable to cascaded acousto-optic filters.

Conclusions:

• The demonstrated two-stage, double-pass acousto-optic filter offers superior performance in sidelobe suppression and bandwidth reduction.
• This integrated-optic device provides a simpler and potentially more cost-effective solution compared to traditional cascaded filters.
• The findings suggest a promising new design for tunable optical filters in various photonic applications.