Accession Number : AD0427005


Title :   DESIGN AND FABRICATION OF OPTICAL FILTERS FOR LASER FREQUENCY.


Descriptive Note : Quarterly progress rept. no. 3, 10 Aug-9 Nov 63,


Corporate Author : SPECTROLAB SYLMAR CALIF


Personal Author(s) : Holmes,Samuel J ; Bowman,Noel


Report Date : 03 Dec 1963


Pagination or Media Count : 26


Abstract : During the period of the past quarter, activity was devoted to various experimental efforts to optimize the basic mica interference filters. From the experimental results, it is now possible to predict the optimum characteristics of the filters that can be obtained from the present type of mica. The final performance of any mica filter is limited only by the optical properties f the mica, for example, absorption and uniformity. Indian pale green mica is reported to have the highest transmission coefficient for any natural mica. Using the measured optical properties of this mica, calculations were made to determine the optimum filter configuration. For the experimental filters, mica half-wave plates coated on both sides with five alternate layers of zinc sulfide and cryolite have been used. The theoretical bandwidth of this type of filter configuration is 0.8 A, and the expected transmission is in the order of 75% without any auxiliary filtering. For a filter employing reflecting stacks of less layers the transmissaon is higher but the rejection of the background outside the passband is much less. (Author)


Descriptors :   *OPTICAL FILTERS , *LASERS , MICA , COATINGS , SODIUM COMPOUNDS , ALUMINUM , FLUORIDES , ZINC COMPOUNDS , SULFIDES , ABSORPTION , MEASUREMENT , REFRACTIVE INDEX , POLARIZATION , TEMPERATURE , SENSITIVITY , TUNING DEVICES


Distribution Statement : APPROVED FOR PUBLIC RELEASE