Aberration Corrected Plane Holographic
Gratings
Specifications
and Control
| Ultimate Specifications |
Standard Specifications |
Control |
|
| Dimension | Up
to 250 mm length |
||
| Radius of Curvature | Superior
at few tens of km |
LTP
Measurements |
|
| Slope Error | Down
to 0.1 arcsec rms |
0.2
arcsec rms |
LTP
Measurements Interferometer |
| Microroughness | Down
to 2 Å rms |
5 Å rms |
Micromap
measurements |
| Substrate | Silicon Fused Silica SiC CVD |
||
| Coating | Au Pt AlMgF Ni |
Cr
binding layer |
Quartz
monitoring |
| Groove Density | Optimised
with JY proprietary software |
Moiré Fringes
(JY patent) Optical control using recording layout (JY patent) |
|
| 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 Fused Silica |
| 150x40x25 |
140x35 |
0.2
arcsec rms |
5 |
Au
or Pt |
Silicon Fused Silica |
100x30x20 |
90x25 |
0.1
arcsec rms |
5 |
Au
or Pt |
Silicon Fused Silica |
Note: Groove density is obtained by interference of two spherical wavefronts
