LASERSPEC-Raman Spectrolab

A unique very high transmission tuneable laser plasma line filter monochromator 210nm to 985nm For Raman & Laser Spectroscopy

Raman Spectroscopy and Plasma Line Blocking

Laserspec is the perfect Laser plasma line filter for Raman spectroscopy Because Raman is a light scattering phenomena, unwanted radiation from laser plasma emission lines are seen superimposed on the Raman spectrum making band assignment difficult and sometimes impossible. Fluorescence from Dye Lasers can also be a considerable nuisance. Laserspec removes this unwanted radiation with little attenuation ensuring spectra free of unwanted spurious lines .

Design.

The optical design of Laserspec is prismatic and takes advantage of the very high transmission and dispersion characteristics associated with prismatic optics . As such Laserspec offers significantly higher transmission than diffraction grating monochromators or other filters and provides significantly better blocking characteristics. Prism materials are selected for each of two wavelength regions, i.e. ultra violet or visible to near infrared.

Dispersion and Spectral Bandwidth

Prisms do not disperse linearly with wavelength due to the change in refractive index with wavelength. For this reason the Laserspec band pass will normally increase as wave length increases. As the monochromator employs a fixed slit as standard it is possible to optimise performance by selecting an appropriate slit width other than the standard slit supplied. In addition the spectral bandwidth isolated will also depend on the laser beam diameter. The performance or blocking efficiency of the monochromator can be optimised if such parameters are taken into account

The LS35 visible-nir prism dispersion optics

Will typically provide the following bandwidths when used with a 1mm non divergent gaussian laser beam

Wavelength in nm   435 486 589 656
Bandwidth in nm      0.23 0.45 1.10 1.70
Wavelength range   430 to 985nm ( optimum )

LS36 ultraviolet to visible prism dispersion optics

Will typically provide the following bandwidths when used with a 1mm divergent gaussian laser beam

Wavelength in nm    220 300 400 450
Bandwidth in nm       0.02 0.03 0.04 0.05
Wavelength range    210 to440nm ( optimum )

Wavelength selection In that Laserspec employs prism optics for light dispersion, so wavelength calibration is not linear. In use the instrument is tuned and optimised to the laser wavelength in use. For ease of use the wavelength indicator is set to coincide with the He Ne wavelength 633nm .

Other Specifications

Max power density 12 W/mm2
Dimensions 235mm X 120mm X 95mm