Acousto-Optic Tunable Filters (AOTFs) Optimised for Operation in the 2-4μm region

6th International Conference on Optical, Optoelectronic and Photonic Materials and Applications 2014

Ward, J.D.^1 ; Valle, S.^1,3 ; Pannell, C.^2 ; Johnson, N.P.^3

Gooch and Housego (UK) Ltd, Dowlish Ford, Ilminster, Somerset

TA19 0PF, United Kingdom^1

Gooch and Housego (Orlando), 4632 36th Street, Orlando

FL

32811, United States^2

Optoelectronics Group, School of Engineering, University of Glasgow, Glasgow

G12 8LT, United Kingdom^3

关键词: Acoustic resonance;    Acousto-optic tunable filters;    Fabry-Perot cavity;    Free-space configurations;    Optical throughput;    Predicted performance;    Spectral imaging system;    Supercontinuum sources;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/619/1/012054/pdf
DOI  :  10.1088/1742-6596/619/1/012054

来源: IOP

【 摘 要 】

Acousto-Optic Tunable Filters (AOTFs) are electronically-controlled bandpass optical filters. They are often preferred in applications in spectroscopy where their agility and rapid random-access tuning can be deployed to advantage. When used for spectral imaging a large aperture (typically 10mm or more) is desired in order to permit sufficient optical throughput. However, in the mid IR the λ2dependence on RF drive power combined with the large aperture can prove to be a hurdle, often making them impractical for many applications beyond about 2μm. We describe and compare a series of specialised free-space configurations of AOTF made from single crystal tellurium dioxide, that require relatively low RF drive power. We report on AOTFs specifically optimised for operation with a new generation of Supercontinuum source operating in the 2-4μm window and show how these may be used in a spectral imaging system. Finally, we describe an AOTF with an (acoustic) Fabry-Perot cavity operating at acoustic resonance rather than the conventional travelling-wave mode; the acoustic power requirement therefore being reduced. We present an analysis of the predicted performance. In addition, we address the practical issues in deploying such a scheme and outline the design of a prototype "resonant AOTF" operating in the 1-2μm region.