Abstract

We describe a wavelength-agile holographic notch filter (WAHNF) suitable for attenuating scattered laser light from the fluorescence signal in laser induced fluorescence (LIF) applications. The WAHNF utilizes a photorefractive material, specifically BaTiO₃, and the technique of two beam coupling to attenuate the coherent portion of the signal to be detected¹. Static holograms recorded in film emulsions are routinely used for this purpose but have the limitation that they are fixed notch-band devices. In contrast, the WAHNF enables tuning or switching the excitation wavelength while passively adapting to maintain the notch band centered on the laser wavelength.

© 1996 Optical Society of America