11 Dec
2000
11 Dec
'00
9:28 a.m.
If anyone knows the spiral spacing off-hand, I could
tell you distance at
which a given wavelength focuses.
The specified track pitch is 1.6 +- 0.1 micron.
Some other specs:
disc:
substrate thickness: 1.2 +- 0.1 mm
refractive index 1.55 +- 0.1
limits for the angular deviation of
reflected beam: +- 1.6 degrees
birefringence of substrate: 100 nm max
limits for reflectivity variation
in program area: 3% for f < 100 Hz
pickup:
wavelength: 780 +- 10 nm
polarization: circular
numerical aperture (NA): 0.45 +- 0.01