Photon etc. hyperspectral imaging and spectroscopic instruments - Spectroscopy

By: Photon Etc  09-12-2011
Keywords: laser, Photon, Laser Beam

Photon etc. hyperspectral imaging and spectroscopic instruments

Photon etc has designed two narrowband tunable filters for resonance . These matched and , based on thick volume Bragg gratings, exhibit a bandwidth less than 10cm-1 and cover a wavelength range of several hundred nanometers.

Raman spectroscopy (RS) is a powerful tool to study the vibrational, optical, and electronic properties of materials in a nondestructive manner. Raman signals are typically orders of magnitude lower than the intensity of the excitation laser line. However, it is possible to significantly increase Raman signals by choosing an excitation wavelength that corresponds to an optical transition of the material under investigation.

Experimental Conditions

Using volume , Photon etc has developed, specifically for RRS, two types of ultra narrow band tunable filters: a and a . The Laser Line Tunable Filter (LLTF) is installed on the Tunable Ti:Saph laser (Figure 2) and blocks the unwanted fluorescence produced by the laser, leaving the excitation laser line untouched. Two steering mirrors (M1 and BS) send the laser line into a standard microscope where the laser beam is focused on the sample of interest. The second filter, a Tunable Top Notch Filter (TTNF), is installed on the microscope. The TTNF blocks the Rayleigh scattering coming from the material, leaving the Raman signal untouched down to 50 cm-1 (20cm-1 has been achieved) with a throughput of up to 80%. The tunable filters are controlled by a computer via USB links, allowing fast wavelength selection.

Results

Stokes and anti-Stokes Raman spectra of single-walled carbon nanotube (SWNT) powder (Figure 1) were measured within less than one hour using a standard spectrometer. Each peak corresponds to a radial breathing mode (RBM), and the center frequency of a given peak is inversely proportional to the nanotube diameter of a given population. Several populations of nanotubes with different diameters can therefore be readily observed and effectively characterized.

MAIN TECHNICAL SPECIFICATIONS


Excitation Wavelength Range   700-1000 nm  or  800-1100 nm
Average Power at the Sample
5 mW
Microscope Objective and Spatial Resolution
50x (< 1 µm)  and  100x (< 0,8 µm)
Detection Range
from 50 cm-1 and up to CCD detection limit (1100nm)

0.6 cm-1

0.2 cm-1
 

 

DETAILED TECHNICAL SPECIFICATIONS

SPECTROMETER


Raman Resolution0.6 cm-1
 0.2 cm-1
Raman Range   from 50 cm-1 and up to CCD detection limit (1100 nm)        
Monochromator Focal Length  500 nm

DETECTOR


CCD type   "Back-illuminated" CCD                          
Cooling System (optional)   Liquid nitrogen cooled EMCCD                                   
     Active Pixels    1340 x 100
    Cooled   1340 x 400
Pixel Size   20 x 20 µm

EXCITATION SOURCE Ti : Saphire CW Laser


Excitation Wavelength   700-1000 nm or 800-1100nm                                                   
Spacial Mode                       TEM00
Polarization   > 100:1 Horizontal
Average Power at the Sample
5 mW
Laser linewidth
< 40 GHz

MICROSCOPE SYSTEM


Objective               50x  , 100x
Spatial Resolution
< 2 µm
Manual Translation of sample                     76 x 52 mm and 250° rotatable                                                

   Sample surface imaging with white light and CCD camera



Bandwidth 0.4 nm (8 cm-1
  0.4 nm (3 cm-1)
Spectral Range   715 - 1000 nm or 800 -1100 nm
                 Peak Transmission
Up to 60%                                                                                


Bandwidth 0.4 nm (8cm-1)

0.4 nm (3 cm-1)                 
Spectral Range
715 - 1000 nm or 800 - 1100 nm                                           
Optical Density
4.0
Signal Out-of-Band Throughput   Up to 80%

Keywords: Hyperspectral Imaging, laser, Laser Beam, Notch Filter, Photon, Raman spectroscopy, Spectroscopic Instruments, Tunable Filter, Tunable Filters,

Other products and services from Photon Etc

09-12-2011

Photon etc. hyperspectral imaging and spectroscopic instruments - Laser Line Tunable Filter

The iris kit is our latest alignment tool designed for our LLTF product line. Photon etc. hyperspectral imaging and spectroscopic instruments.


09-12-2011

Photon etc. hyperspectral imaging and spectroscopic instruments - Tunable Top Notch Filter

Our Tunable Top Notch Filter is a compact, easy to align instrument with an intuitive user interface that allows easy and precise control of the blocked wavelength. The Tunable Top Notch Filter has a high throughput, with a selectivity similar to that of a triple spectrograph, but at a fraction of the price. Photon etc. hyperspectral imaging and spectroscopic instruments.


09-12-2011

Photon etc. hyperspectral imaging and spectroscopic instruments - Tunable Sources

New developments in super-continuum white laser technology allow the full visible or NIR wavelength range to be produced by a single source. Photon etc’s technology and design make it an ideal tool for work in instrumentation labs as well as on telescopes. 4s to move from min wavelength on one grating tomax wavelength on another grating. Photon etc. hyperspectral imaging and spectroscopic instruments. Output power can reach up to 100 ?W/nm.