Patent ID: 7545493
Filing Date: 2009-06-09
Classification: G01J,G01N

Abstract:
1. A spectroscopic apparatus for measuring the Raman spectrum of a physical material, the apparatus comprising: a broad stripe diode laser with a monolithically integrated narrowband internal grating for producing a laser beam with high spectral and spatial brightness; an optical system for delivering said laser beam to a physical material to excite a scattered optical signal, and for extracting a Raman scattering signal from the scattered optical signal, said optical system maintains the spatial brightness of said laser beam; and a spectrograph for measuring the relative intensity of different wavelength components of the Raman scattering signal to obtain a Raman spectrum; wherein the internal grating acts as a distributed Bragg reflector (DBR) to lock the laser wavelength to a Bragg wavelength set by a period associated with said internal grating and to narrow down a spectral linewidth of the laser.