DDHR Grating Spectrometer
The DDHR (double-diffraction high-resolution) grating spectrometer gives the unique opportunities in terms of high etendue, fine spectral resolution and extremely high sensitivity to solve spectral-analytical problems even in the most challenging conditions.
- Very high spectral resolution λ/Δλ up to 105
- High etendue: F/5.4, slit height 10mm
- Matrix detector EMCCD camera Andor Ixon Ultra DU-897 (sensitivity - dozen photons)
- Large spectral range coverage λ/d from 0.65 to 1.4
- Excellent stray light rejection
- Compact design
- High image quality
The spectrometer can be equipped with EMCCD camera Andor Ixon Ultra DU-897 where the amplification occurs when a charge in output register is clocked and has sufficient energy to create another electron-hole pair, - an analogue of avalanche amplification regulated up to single photon sensitivity.
Key advantages
- The large dispersion and high throughput grating spectrometer operates in the first order of diffraction.
- The angular dispersion invariant to wavelength tuning is the advantage offered by the mount.
- In a condition of enhanced angular dispersion specific to the large diffraction angles, the spectral resolving power is no more limited by aberration image blur that results in use of a short focal length imaging optics permitting simplicity and compactness of the design.
- The spectrometer flux luminosity is compared with Fabry–Perot interferometer of the same resolving power!
- The use of the first diffraction order permits to combine the large angular dispersion and a broad free spectral range under the neighboring orders negligible overlap.
Main characteristics
| Characteristic | Min | Typical | Max | ||
| Grating, groove/mm | 2400 | 1800 | 1200 | ||
| Spectral Range, nm | 300-700 | 400-900 | 600-1350 | ||
| Focus, mm | 300 | ||||
| F# | F/5.4 | ||||
| Slit height, mm | 10 | ||||
| Relative dispersion, nm/mm | 0.15 | 0.2 | 0.3 | ||
| Limited Spectral resolution (slit 0.02 mm) | 0.003 | 0.004 | 0.006 | ||
Comparison with Jobin Yvon polychromators
| Model | THR1000 | 1000M | U1000 (double) | 1250M | DDHR |
| Company | Jobin Yvon | Jobin Yvon | Jobin Yvon | Jobin Yvon | Spectral Tech |
| Focus, mm | 1000 | 1000 | 1000 | 1250 | 300 |
| F# | F/7.5 | F/8 | F/8 | F/9 | F/5.4 |
| Relative dispersion, nm/mm | 0.8 | 0.8 | 0.4 | 0.65 | 0.2 |
| Limiting spectral resolution (slit 0.02mm) | 0.008 | 0.008 | 0.004 | 0.006 | 0.005 |