Scanning Mirror LSM Series

IntroductionScanning Mirrors
The LSM series of scanner mirrors are rectangular silicon components of light weight, intended for
general-purpose use in high-speed single axis scanner systems.
The dimensions of each mirror have been calculated to allow for scanning of a CO2 laser beam at
up to 30 degrees off-axis with no beam spillover at the extremes of scan.
LSM mirrors have high reflectivity (low absorption) and so may be used safely at high laser powers.
Technical specifications
Dimensions : See Table 10.311.
Incidence angle : 45±15°.
Flatness : Better than λ/20 at 10.6μm.
Material : Monocrystalline mirror-grade Si.
Mass : See Table 10.311.
Coating : SuperMax (See TDS 15.10)
Coating jig lip : Maximum 0.8mm along long edges.
Reflectivity : >99.6% at 10.6μm.
Absorption : <0.35% at 10.6μm.
Dimensional tolerances : Length / width… +0/-0.1mm.
Thickness… ±0.1mm.

Scannning Mirror Data

Notes on table 10.311
All dimensions are in millimetres. Masses are in grammes.
The diameter ‘D1’ is the maximum recommended diameter for the full beam size (ie:- 99% power
points), and ‘D2’ is the maximum recommended 1/e² beam diameter.
Material, coatings and quality
The silicon used to fabricate the LSM mirrors is high-specification monocrystalline material, whose
doping makes it suitable for reflective applications.
These mirrors are polished to a surface accuracy of λ/20 or better, and coated with a low absorption
maximum-reflector coating for 10.6μm. The coating is designed for use with continuous-wave
(CW) CO2 laser beams at an incidence angle of 45°.
Intrinsic CW LIDT exceeds 500W/mm of beam diameter (1/e2 intensity points).
Custom-made products
For scanning mirrors of other sizes please call or fax, specifying your values for length, width and
thickness. Please note that, for fast-scanning applications, it may be counter-productive to specify
mirrors which are too thin, since distortion in use may overcome the benefits of reduced mass.