Vacuum UV Spectroscopy
Variable Line Space Plane Holographic Gratings
Specifications and Control
| - | Ultimate Specification | Standard Specification | Control |
|---|---|---|---|
| Dimension | Up to 250 mm length | - | - |
| Radius of Curvature | Down to 0.01% | 0.5% | Calibrated Samples LTP measurements |
| Slope error | Down to 0.1 arcsec rms | 0.2 arcsec rms | LTP measurement Interferometer |
| Microroughness | Down to 2 Å rms | 5 Å rms | Micromap measurements |
| Substrate | Silicon Zerodur Fused Silica SiC CVD | - | - |
| Coating | Au Pt AlMgF Ni | Cr binding layer | Quartz monitoring |
| Groove Density | Follows a polynomial law Recording layout using JY proprietry software Optical ray tracing of the monochromator | Moiré Fringes (JY patent) LTP measurement | |
| Efficiency | Groove depth and duty cycle ratio optimised with JY proprietary software | ||
| Groove Depth | +/- 5% | +/- 10% | AFM measurements |
| c/d Ratio | +/- 5% | +/- 10% | AFM measurements |
Examples of Aberration Corrected Plane Holographic Gratings
| Size mm | Optical surface mm | Slope Error arcsec rms | Max Microroughness Å rms | Coating | Substrate |
|---|---|---|---|---|---|
| 200x50x30 | 190x45 | 0.2 arcsec rms | 5 | Au or Pt | Silicon Zerodur Fused Silica |
| 150x40x25 | 140x35 | 0.2 arcsec rms | 5 | Au or Pt | Silicon Zerodur Fused Silica |
| 100x30x20 | 90x25 | 0.1 arcsec rms | 5 | Au or Pt | Silicon Zerodur Fused Silica |
Note: Recording wavefronts are either two spherical, one spherical and one aspherical or both aspherical depending on the required polynomial.