Raman Spectrometer Laboratory

Phone : +91-3222-283856

Location : OB / GF / 2, CRF

Facilitator : Prof. Anushree Roy, Physics
Email: anushree@phy.iitkgp.ernet.in, Contact:+91-3222-283856



Objectives


(some examples in some fields)

In geological material analysis:
chemical identification
characterization of molecular structure
effect of bonding, environment and stress


In chemistry Phase identification
Characterization of molecular structure


In biology/medicine
As non-invasive diagnostic tool
Biochemical information
Protein conformation


In material science
Material characterization


In physics
Electron phonon interaction
Electronic resonance effect in phonons
Dynamics of fractal network
Behaviour of Acoustic phonon
Surface science

In art
For restoration/conservation


Other fields, where the technique is used extensively

Biosecurity
Display Technologies
Environmental
Food & Beverages
Forensic
Industrial Process
Nanotechnology
Cosmetics
Photovoltaic / Solar Cell

People


Prof. Anushree Roy
Facilitator
Physics
anushree@phy.iitkgp.ernet.in
+91-3222-283856
Miss Ritashri Pradhan
Technical Staff
Central Research Facility
ritashri96@adm.iitkgp.ac.in

Equipment Details


RAMAN SPECTROMETER

Excitation source: Argon-Krypton mixed ion gas laser. MODEL 2018 RM (Make Spectra Physics, USA) 

Spectrometer : MODEL T64000 (Make Jobin Yvon Horiba, France) 

Detector : Thermoelectric cooled front illuminated 1024 256 CCD. MODEL SynpseTM (Make Jobin Yvon Horiba, France) 

Collection Optics: Optical Microscope MODEL BX41 (Make Olympus, Japan)

TECHNICAL SPECIFICATIONS:

 

Basic Configuration Optical Diagram for the Spectrometer

  1. Axial entrance slit
  2. Aberration corrected holographic grating
  3. Fixed mirror
  4. Intermediate slit
  5. Fixed mirror
  6. Aberration corrected holographic grating
  7. Slit to spectrograph
  8. Manual intermediate slit
  9. Fixed mirror
  10. Aberration corrected holographic grating
  11. Fixed mirror

     Round plates: Fixed mirrors

 

Presently Available Configuration: Single Monochromator Configuration (Double Subtractive Mode)

 

The double subtractive foremonochromator is used as an tunable filter in the spectral range defined by the scanning mechanism and the gratings. A polychromatic radiation enters the first monochromator through the entrance slit S1 and is dispersed by the grating G1. The exit slit of the first monochromator (entrance slit of the 2nd monochromator) Si1/2 selects a bandpass between l1 and l2. The grating G2 in the 2nd monochromator recombines all the dispersed radiations on the exit slit Si2/3 giving again a polychromatic radiation, but limited to only the spectral range between l1 and l2. The polychromatic radiation selected by the foremonochromator between l1 and l2  is dispersed by the grating G3 of the spectrograph. The spectrum is acquired with a multichannel detector which is mounted in the plane of the exit image or with a monochannel detector through an exit slit. See following diagram.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Focal length of the spectrometer for present configuration: 640mm

Low frequency: < 100 cm-1

Step size: 0.00066 nm (0.03 cm-1)

Grating: 1800 grooves/mm

Grating efficiency curve

 

 

Table for dispersion and resolution

 

Wavelength of excitation source

(nm)

Corresponding

wavenumber

(cm-1)

Dispersion

(cm-1/mm)

Total dispersion on CCD chip*

(cm-1)

Dispersion

/pixel**

(cm-1)

Resolution (Min. 3 pixels

to define a peak)

(cm-1)

400

25000

46.55

1210.3

1.18

3.54

500

20000

27.83

723.58

0.71

2.13

600

16667

17.86

464.36

0.45

1.35

700

14286

11.53

299.78

0.29

0.87

*dimension of the chip 26 mm´26 mm ** CCD format 1024´256

Basic specification for the CCD

CCD format: 1024´256 Front illuminated open electrode CCD

Pixel size: 26 mm´26 mm

     Quantum efficiency

 

 

Basic specification for the laser

 

Wavelength and Maximum Power

Wavelength of excitation source

(nm)

Laser Power

at laser head

(mW)

Power

on the sample

using

10´ objective

(mW)

487.986

200

15

514.532

220

15

647.088

220

22

 

(note: it is only  power not power density on the sample)

 

 

Collection optics

Visible confocal microscope with X-Y manual mechanical stage

and a revolver equipped with 3 achromatic objectives

10´ visible, NA= 0.25, WD=10.6 mm

50´ visible, NA= 0.75, WD=0.37 mm

100´ visible, NA= 0.90, WD=0.21 mm

 

Measurements will be carried out at room temperature

 

PURCHASE SOURCE:

Institute Funding, Year Of Installation September 2011

Utility and Working Principal



Sample Details


SAMPLES  PREPARATION FOR MEASUREMENTS

Sample Preparation Required: Nil

Please bring micropipette or special spatula, if they are required to handle the sample.

VOLATILE SAMPLES ARE STRICTLY PROHIBITED.

POWDERED SAMPLE WILL BE ENTERTAINED ONLY WITH 10´ MICROSCOPE OBJECTIVE.



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