1. See R. A. Smith, F. E. Jones and R. P. Chasmar,The Detection and Measurement of Infrared Radiation (@#@ Oxford Univ. Press, 1968), Chap. I.
2. Sir William Herschel, Phil. Trans. Roy. Soc.90, 284, 437 (1800).
3. W. T. Case, Phys. Rev.9, 305 (1917); 15, 289 (1920).
4. P. W. Kruse, L. D. McGlauchlin, and R. B. McQuistan,Elements of Infrared Technology: Generation, Transmission, and Detection (Wiley & Sons, New York, 1962).
5. R. A. Smith, F. E. Jones, and R. P. Chasmar,The Detection and Measurement of Infra-red Radiation (Oxford Univ. Press, 1968).