Vacuum UV Spectroscopy

Constant Ruling Density Spherical Holographic Grating

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 Deviation less than 0.1 gr/mm Moiré Fringes (JY Patent) Optical control using recording layout (JY Patent)  
Efficiency Groove depth and duty cycle ratio optimised by JY proprietary software according to required optical layout    
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