Plano-Convex Rectangular Cylindrical Lenses

Plano-concave rectangular cylindrical lenses provide uni- axial negative imaging for anamorphic beam expansion and a wide range of applications.These lenses may also be used as mirror blanks if a concave cylindrical surface mirror is required.

1.  Germanium (Ge)

Germanium (Ge) is the preferred lens and window material for high performance infrared imaging systems in the 8–12 μm wavelength band. Its high refractive index makes Ge ideal for low power imaging systems because of minimum surface curvature. Chromatic aberration is small, often eliminating the need for correction.

2. Silicon (Si) 

Silicon (Si) is grown by Czochralski pulling techniques (CZ) and contains some oxygen that causes an absorption band at 9 microns.To avoid this, material can be prepared by a Float-Zone (FZ) process. Optical silicon is generally lightly doped (5 to 40 ohm cm) for best transmission above 10 microns, and doping is usually boron (P-type) and phosphorus (N-type). After doping silicon has a further pass band: 30 to 100 microns which is effective only in very high resistivity uncompensated material.
 
CZ Silicon is commonly used as substrate material for infrared reflectors and windows in the 1.5-8 micron region. The strong absorption band at 9 microns makes it unsuitable for CO2 laser transmission applications, but it is frequently used for laser mirrors because of its high thermal conductivity and low density. Application as window, lens in the 1.5 - 8 um region; Mirror for CO2 laser and spectrometer applications.
 

ZnS MultiSpectral Under intense heat and pressure, defects within the crystalline lattice are virtually eliminated, leaving a water-clear material with minimal scatter and high transmission characteristics from 0.4 to 12 microns. This material is particularly well suited for high-performance common aperture systems that must perform across a broad wavelength spectrum.

Specifications:

Material: ZnS MultiSpectral
Diameter Tolerance: --------------------- +0.0, -0.1mm
Thickness Tolerance: -------------------- ±0.1mm
Clear Aperture: ---------------------------->85%
Parallelism: -----------------------------------3 arc minute
Surface Quality: ----------------------------80-50 scratch and dig
Wavefront Distortion: -------------------- λ /2 per 25mm @633mm
Bevel: -----------------------------------------Protective  (<0.2mm x 45° )
Coating: -------------------------------------- Optional （Uncoated, AR Coating, etc.）

4. ZnSe material

ZnSe is a preferred material for lenses, windows, output couplers and beam expanders for its low absorptivity at infrared wavelengths and its visible transmission. For high-power applications, it’s critical that the material bulk absorption and internal defect structure be carefully controlled, that minimum-damage polishing technology be employed, and the highest quality optical thin-film coatings are used. The material absorption is verified by CO2 laser vacuum calorimetry. Our quality assurance department provides testing and specific optics certification on request.

ZnSe is non-hygroscopic and chemically stable, unless treated with strong acids. It’s safe to use in most industrial field, and laboratory environments.

1、What Metallic Coated types can Uni-Optics supply?

Uni-Optics mainly offers four coating types, including:

1) UV Enhanced Aluminum : Ravg > 85% from 250nm to 400nm

2) Protected Aluminum: Ravg > 87% from 400nm to 800nm

3) Protected Silver: Ravg > 95% from 400nm to 20um

4) Protected Gold: Ravg > 98% from 650nm to 16um

2、What are features of Metallic coated mirror?

Metallic coated mirror have many key features below:

Wide spectral range

Not sensitive to the incidence angle and polarization state

Low cost

Non-durable

Relatively low reflectance

Low laser damage threshold

3、What UNI Optics can do for you?

Common Specifications:

Substrate Materials: N-BK7, Fused silica, Pyrex；Float glass

Dimensional tolerance: +/-0.1mm

Surface quality:  60-40

Parallelism:  3’

Flatness: λ/4 per 25mm@633nm

Bevel: Protective

One surface: Polished and Metallic coating

The other surface: Fine ground

Note: Aluminum is the most widely used metal reflection film, from near UV to near IR, have high reflectivity, and with low cost. Silver has higher reflectivity in the visible and near infrared wavelength than the aluminum film, but the silver in the air will be rapid oxidation, color darkening, makes the film performance and firmness declined rapidly. Gold film has a good consistency with high reflectivity in the near, middle and far infrared range, can control the thermal radiation effectively, but it is relatively soft, easy bruising, and should be pay very attention to clean, and the cost is very high.