Abstract

A sensitive and versatile spectrophotometer for differential or absolute reflectance and transmittance measurements is described. Special sample configurations are not required, and the sample may be subjected to almost any type of external perturbation. A transparent refracting chopper is used to obtain separate sample and reference beams. A synchronous electronic circuit is used to measure the reference and sample signals while suppressing the intervening switching transients. The fractional absolute error is less than ±10−2. The peak-to-peak instrument noise is approximately 2 × 10−5 of the reference signal. Thus, changes in reflectance or transmittance as small as a few parts in 105 can be seen. In many cases this approaches the shot noise limit and is comparable to the sensitivity obtainable with modulation techniques. Examples of results for the reflectance of InP near 3.2 eV and GaAs near 1.8 eV are given.

© 1970 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Scanning Ultrahigh Vacuum Reflectometer

T. Huen, G. B. Irani, and F. Wooten
Appl. Opt. 10(3) 552-556 (1971)

Spectrophotometer for measuring spectral reflectance and transmittance

Peiyun Wu, Peifu Gu, and Jinfa Tang
Appl. Opt. 33(10) 1975-1979 (1994)

Spectrophotometer for measuring small sharp absorption bands in solids at low temperatures

John Rolfe and H. J. Labbe
Appl. Opt. 19(12) 1937-1940 (1980)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (5)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (4)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription