Glacier X
TE Cooled CCD Spectrometer
1. Fiber Coupler
Secures Fiber to Ensure Repeatable Results
By coupling a fiber optic to the SMA 905 adaptor, light will be guided to the slit and optically matched, ensuring reproducibility. For free space sampling, a diffuser or lens assembly can be connected directly to the SMA 905 adaptor.
2. Entrance Slit
Determines Photon Flux and Spectral Resolution
Light entering into a spectrometer’s optical bench is vignetted by a pre-mounted and aligned slit. This ultimately determines the spectral resolution and throughput of the spectrometer after grating selection. We offer a variety of slit widths to match your specific application needs: from 10μm - 200μm wide, with custom slits available.
3. Collimating Mirror
Collimates and Redirects Light Towards Grating
Both mirrors are f/# matched focusing mirrors with UV enhanced coating, which produces approximately 95% reflectance when working in the UV-Vis spectrum.
4. Diffraction Grating
Diffracts Light, Separating Spectral Components
The groove frequency of the grating determines two key aspects of the spectrometer’s performance: the wavelength coverage and the spectral resolution. When the groove frequency is increased, the instrument will achieve higher resolution, but the wavelength coverage will decrease. Inversely, decreasing the groove frequency increases wavelength coverage at the cost of spectral resolution. The blaze angle or blaze wavelength of the grating is also a key parameter in optimizing the spectrometer’s performance. The blaze angle determines the maximum efficiency that the grating will have in a specific wavelength region.
5. Focusing Mirror
Refocuses Dispersed Light onto Detector
Both mirrors are f/# matched focusing mirrors coated with AlMg2, which produces approximately 95% reflectance when working in the UV-Vis spectrum. Aluminum (Al) provides reflectance and magnesium (Mg2) protects the aluminum from oxidation.
6. Array Detector
Measures Entire Spectrum Simultaneously
The Glacier® X features a 2048 x 1 linear TE Cooled CCD array detector with a 14μm pixel width and > 2000 active pixels. As the incident light strikes the individual pixels across the CCD, each pixel represents a portion of the spectrum that the electronics can then translate and display with a given intensity using BWSpec™ software.
The quantum efficiency (QE) and noise level of the array detector greatly influences the spectrometer’s sensitivity, dynamic range and signal-to-noise ratio. The spectral acquisition speed of the spectrometer is mainly determined by the detector response over a wavelength region.
7. Thermoelectric Cooler
Reduces Dark Noise and Increases Detection Limits
Cooling an array detector with a built-in thermoelectric cooler (TEC) is an effective way to reduce dark current and noise, as well as to enhance the dynamic range and detection limit.
When the CCD detector array is cooled from a room temperature of 25°C down to 14°C by the TEC, the dark current is reduced by a factor of 4 and the dark noise is reduced by a factor of 2. This allows the spectrometer to operate at longer exposure times and to detect weaker optical signals.
