Light trimming of a narrow bandpass filter based on a photosensitive chalcogenide spacer.
We present an experimental study of the photosensitive properties of a narrow bandpass filter based on a Ge(15)Sb(20)S(65) spacer fabricated by electron beam deposition. For a single layer, near the optical bandgap of this chalcogenide material, the efficiency of the photo-bleaching increases as the central wavelength of the light source for exposure decreases. The maximum relative photo-induced change of the optical thickness reaches about 1%. By using controlled light exposure around 480 nm of a photosensitive narrow bandpass filter centered at 1550 nm, we obtained a spatially localized shift of its peak wavelength up to 5.4 nm. This property is used to perform, for the first time at our knowledge, the post trimming of a narrow bandpass filter with a light beam. A 5 x 5 mm(2) ultra uniform area in which the relative spatial variation of its peak wavelength remains below 0.004% is demonstrated.
Institut FRESNEL, UMR CNRS 6133, Université Paul Cézanne - Ecole Centrale Marseille - Université de ProvenceDomaine Universitaire de Saint-Jérôme, 13397 Marseille Cedex 20, France.
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Shen
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Cathelinaud
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Lequime
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Charpentier
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Nazabal
D018011:Chalcogens / Q000737:chemistry*; D005374:Filtration / Q000295:instrumentation* / Q000379:methods; D008567:Membranes, Artificial; D055095:Optics and Photonics / Q000295:instrumentation*; D010777:Photochemistry / Q000379:methods*
D018011:Chalcogens; D008567:Membranes, Artificial