Spectrometers > Non-scanning Dispersive Raman Spectrometers
Description
Typical Raman signal is very weak, so that very high sensitivity spectrometers are needed to measure it. This is where P&P Optica's high performance systems fit in. Our volume phase holographic (VPH) diffraction gratings and transmission based design spectrometers are ideal for Raman applications. The non-scanning Raman spectrometer allows for the measurement of weak signals from dynamically changing samples.
Our Raman spectrometers are an extension of the wide spectral range high performance systems which were designed to deliver high throughput with minimal signal aberrations. For Raman applications, the VPH grating dispersion was increased significantly to increase the spectral resolution and to decrease the spectral range. The optics of the system were also modified to provide even better aberration control - thus allowing for the use of very tall slits and high detectors.
Figure 1. Smaple Raman spectrum obtained with P&P Optica dispersive, non-scanning spectrometer (top) and a typical Raman FT system
What does this mean to a Raman spectrometer user?
P&P Optica Raman spectrometers collect much more light than typical non-scanning Raman systems. That gives you ability to measure signals not measurable before, as the signal to noise (SNR) of the system improves greatly.
Our Raman spectrometer can collect light from slits up to 12 mm in length, providing high signal without sacrificing the resolution of the system. The low aberration optics permit the use of very thin slits, down to 10 microns and detector pixels of 12 microns - giving very high spectral resolution in a non-scanning spectrometer.
Available Systems
| Product Name1 | Units | Excitation wavelength | Shift from excitation | Start of spectrum | Spectral band | End of spectrum | Dispersion per pixel | Spectral resolution2 |
|---|---|---|---|---|---|---|---|---|
| RASPPEC-532nm-F | cm-1 | 18797 |
70 |
18727 |
9398 |
9398 |
5.14 |
10.27 |
| nm | 532 |
2 |
534 |
530 |
1064 |
0.29 |
0.58 |
|
| RASPPEC-532nm-HR | cm-1 | 18797 |
53 |
18744 |
3453 |
15344 |
1.89 |
3.77 |
| nm | 532 |
2 |
533 |
118 |
652 |
0.06 |
0.13 |
|
| RASPPEC-785nm-F | cm-1 | 12739 |
73 |
12666 |
3793 |
8946 |
2.07 |
4.15 |
| nm | 785 |
5 |
790 |
328 |
1118 |
0.18 |
0.36 |
|
| RASPPEC-785nm-HR | cm-1 | 12739 |
65 |
12674 |
2147 |
10591 |
1.17 |
2.35 |
| nm | 785 |
4 |
789 |
155 |
944 |
0.09 |
0.17 |
|
| RASPPEC-1064nm-F | cm-1 | 9398 |
70 |
9328 |
3618 |
5780 |
3.53 |
7.07 |
| nm | 1064 |
8 |
1072 |
658 |
1730 |
0.64 |
1.28 |
|
| RASPPEC-1064nm-HR | cm-1 | 9398 |
53 |
9346 |
1565 |
7834 |
2.48 |
4.96 |
| nm | 1064 |
6 |
1070 |
207 |
1277 |
0.38 |
0.75 |
1 Modular design allows for custom camera and detector fitting as required by the customer.
2 Performance data for excitation bandwidth <= 1cm-1
System Options
These are examples of Raman system configurations offered by P&P Optica. Please contact us for more information regarding these and any other systems.
High Performance Raman Spectrometer for 785 nm excitation wavelength (RASPPEC-785nm-F)
- High performance spectrometer with VPH grating
- <0.01% scattered light level
- 300cm-1 spectral range
- 3.25cm-1/pixel mean dispersion
- installed and tested 500mW, 785nm, 3.5cm-1 line width LD
- IR enhanced Hamamatsu linear array detector, 1TEC cooled, SNR>1000
- 1.5m, 300-3000cm-1, 0.2mm core diameter fiber optic probe
Option 1: Back thinned Hamamatsu detector, 1TEC cooled, 1.6mm, 2D array, SNR>3000
Option 2: Back thinned Hamamatsu detector, 2TEC cooled, 1.6mm, 2D array, SNR>3000 reduced dark noise for weak signals
Option 3: 785 nm 300mW laser, 1.0cm-1 line width
Option 4: 786 nm 600mW laser, 1.0cm-1 line width
Option 5: 5m, 200-3000cm-1 fiber optic probe
Option 6: < 50-3000cm-1 Raman probe with fiber optic delivery and light redistribution, matched to a spectrometer with back thinned Hamamatsu detector, 2TEC cooled, 6mm tall, 2D array, SNR>10,000 and reduced dark noise for weak signals
Option 7: Sample holder for variable diameter cylindrical test tubes
High Resolution, High Performance Raman Spectrometer for 785 nm excitation wavelength (RASPPEC-785nm-HR)
- High performance spectrometer with VPH grating
- <0.01% scattered light level
- 2000cm-1 spectral range
- 2cm-1/pixel mean dispersion
- installed and tested 300mW, 785nm, 1cm-1 line width LD
- Back thinned Hamamatsu detector, 2TEC cooled, 6mm tall, 2D array, SNR>10,000 reduced dark noise for weak signals
Option 1: < 50-2000cm-1 Raman probe with fiber optic delivery and light redistribution, matched to a spectrometer with back thinned Hamamatsu detector, 2TEC cooled, 6mm tall, 2D array
Option 2: Sample holder for variable diameter cylindrical test tubes
Option 3: installed and tested 600mW, 785nm, 1cm-1 line width LD
Technical Specifications
| Parameter | Value |
|---|---|
| size | 32cm L x 12cm W x 10 cm H |
| weight | typically <2 kg without detector |
| F/number | F/3 |
| Spectral range (free of second order effects) | 30% of an octave in the 350 nm to 2500 nm range |
| Spot diameter | 19 µm @ 1000 nm in 25.4 x 9 mm2 area |
| Spectral resolution (0.024 mm wide pixels) | 0.13 nm @ 532 nm and 0.17 785 @ 2000 nm |
| Linear dispersion | 30% of an octave per inch |
| Maximum detector size | 25.4 x 12.7 mm |
| Dynamic range of a single 0.024 by 0.024 mm2 pixel | > 3,000 |
| Dynamic range, binning along 2 mm slit | > 55,000 (detector dependent) |
| Dynamic range, binning along 8 mm slit | > 300,000 (up to 1,000,000 with averaging over a number of measurements) |
