Sub-Wavelength Imaging of Photo-Induced Refractive Index Pattern in Chalcogenide Glass Films
- Amy
Mapping of refractive index patterns with sub-wavelength resolution is achieved using Near-field Scanning Optical Microscopy (NSOM) in reflection mode. Imaging of index pattern is performed on surface gratings photo-imprinted in As2S3 films. The NSOM is adapted with a near infrared laser which wavelength (785 nm) is chosen to be within the transparency window of the glass film therefore allowing consistent measure of reflected light. Quantitative measurements of photo-induced index changes can then be obtained from knowledge of the initial film index. Images of gratings with a period of 0.5 micron are easily collected therefore demonstrating sub-wavelength spatial resolution. The technique permits to concurrently obtain a topographic image and index image of the gratings thereby permitting to quantify the extent of photodarkening and photoexpansion simultaneously. It is shown that relief gratings tend to vanish in films aged in air for several months however the index gratings remain.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 989044
- Report Number(s):
- PNNL-SA-69044; NN2001000; TRN: US201019%%176
- Journal Information:
- Optics Communications, 282(22):4370-4373, Vol. 282, Issue 22; ISSN 0030-4018
- Country of Publication:
- United States
- Language:
- English
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