Title :
A fiber-optic autocollimation refractometric method for dispersion measurement of bulk optical materials using a widely tunable fiber Raman laser
Author :
Ilev, Ilko K. ; Kumagai, Hiroshi ; Toyoda, Koichi
Author_Institution :
RIKEN, Inst. of Phys. & Chem. Res., Saitama, Japan
fDate :
11/1/1996 12:00:00 AM
Abstract :
A simple and highly sensitive fiber-optic autocollimation method for refractive-index dispersion measurement of solid-state and liquid bulk optical materials is presented. The method is based on the use of a double-pass multimode fiber Raman laser which generates widely tunable emission in a broadband (0.54-1.01 μm) continuous spectral range at pumping with the second harmonic of a Q-switched Nd:YAG laser. The optical fiber is used in a specific multifunctional regime where, because of its micrometric core dimensions, it serves simultaneously as a point laser source for the formation of a collimated input emission, as a highly sensitive receiver of the autocollimation backreflectance, and as a medium for nonlinear frequency conversion and generation of a broad-band continuum spectrum. The experimental results obtained in the refractive-index dispersion measurements are fitted to the Sellmeier dispersion equation and used to determine the material dispersion and additional dispersive characteristics of the test optical material
Keywords :
Raman lasers; fibre optic sensors; measurement by laser beam; optical collimators; optical dispersion; optical frequency conversion; optical materials; optical pumping; photodetectors; refractive index; refractive index measurement; sensitivity; 0.54 to 1.01 mum; Q-switched Nd:YAG laser; YAG:Nd; YAl5O12:Nd; autocollimation backreflectance; broad-band continuum spectrum; bulk optical materials; collimated input emission; continuous spectral range; dispersion measurement; double-pass multimode fiber Raman laser; fiber-optic autocollimation refractometric method; highly sensitive fiber-optic autocollimation method; highly sensitive receiver; liquid bulk optical materials; micrometric core dimensions; multifunctional regime; nonlinear frequency conversion; nonlinear frequency generation; point laser source; refractive-index dispersion measurement; refractive-index dispersion measurements; second harmonic; widely tunable emission; widely tunable fiber Raman laser; Fiber lasers; Laser excitation; Optical fiber dispersion; Optical harmonic generation; Optical materials; Optical refraction; Pump lasers; Solid state circuits; Stimulated emission; Tunable circuits and devices;
Journal_Title :
Quantum Electronics, IEEE Journal of
