Abstract

A double-beam wavelength-modulated reflectometer utilizing a single detector and without a reflectivity reference has been described. Separate electronic channels are used for the two wavelengths at which the reflectometer alternatively operates. The gain of one of the channels is controlled by feedback to eliminate the instrumental background. The derivative and conventional reflectivity are measured simultaneously. The influence of the photomultiplier dark current and scattered light on the accuracy and of some design parameters on the SNR have been evaluated. The system has been checked by measuring the derivative and conventional reflectivity spectrum of GaAs.

© 1974 Optical Society of America

Rotating Beam Splitter for the Extreme Vacuum Ultraviolet

W. Gudat, C. Kunz, and J. Karlau
Appl. Opt. 13(6) 1412-1416 (1974)

Infrared Reflectometry with a Cavity-Shaped Pyroelectric Detector

W. R. Blevin and Jon Geist
Appl. Opt. 13(10) 2212-2217 (1974)

Use of Channel Electron Multipliers as Secondary Standard Detectors at EUV Wavelengths

J. G. Timothy and L. B. Lapson
Appl. Opt. 13(6) 1417-1430 (1974)

Simple derivative optical spectrometer

G. Baldini, E. Grilli, and M. Guzzi
Appl. Opt. 14(11) 2687-2690 (1975)

Dichroic microspectrophotometer: A computer-assisted, rapid, wavelength-scanning photometer for measuring linear dichroism in single cells*

Ferenc I. Hárosi and Edward F. MacNichol
J. Opt. Soc. Am. 64(7) 903-918 (1974)