The advent of effective solid -state pulse lasers operating in the 3 -µm range [1,2] that became available during the last ten years sets forth the problem of designing methods of registration and visualization of laser radiation within this range. Today, a researcher may choose from a good number of IR radiation visualization techniques resting upon the effect of a change of properties in various materials under the influence of heat [3]. In terms of such indicators as sensitivity, dynamic range, resolution, as well as a number of operational characteristics, the "thermal sensitization" technique applied to silver-halide photoemulsions [4] is far superior to any other available technique for visualization of IR radiation pulsed laser fields. This technique has been originally applied to photoregistration of pulsed gas laser radiation in the range of 5 and 10 µm. This paper presents the results of the experimental study of the potential of the method for registration of a YAG:Er3+ laser radiation at k = 2.94 pm. The following parameters were determined: sensitivity, 2 mJ /cm2; dynamic range, 100; resolution with the generation pulse duration of 200 µs, not worse than 50 lines /mm. Spectral sensitivity of silver -halide photoemulsions is known to be limited to a wavelength of 1.3 pm. It turns out that the use of the thermal sensitization method permits the use of conventional films for registration of the IR radiation far beyond this boundary. The method is based upon the effect of an increase of the photolayer sensitivity with temperature widely used in photography. As proved by the experimental study, the process of IR photoregistration may be presented as follows. The absorbtion of the IR radiation by the film produces a temperature relief on the photo layer that leads to local changes of the sensitivity. With a small time of IR radiation effect upon the film when heat transfer in the photoemulsion is negligible this temperature relief corresponds to the distribution of the incident IR radiation intensity. The temperature field is visualized by means of the subsequent exposure of the film.The sensitivity of the technique depends upon the absorbability of the photoemulsion at a given IR range wavelength. Fig. 1 shows the absorption spectrum of the photoemulsion and the triacetate base within the range of 2 thru 10 ltm recorded on a IKS -22 spectrophotometer. As seen from the presented spectra, the areas of maximum absorbtion are those in the ranges 2.8 thru 3.5, and 6 thru 10 pm.The radiation of the YAG:Er3+ laser was photorecorded on high contrast technical film FT -101 with a sensitivity 0.2 GOST units and a resolution of 100 lines per mm.The potential of the technique was studied on the installation depicted in Fig. 2. The YAG:Er3+ laser (A = 2.94 pm)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.