Beam splitter Plate

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Beamsplitter plate is a plate of glass with a thin coating of aluminium (usually deposited from aluminium vapor) with the thickness of the aluminium coating such that part, typically half, of light incident at a 45 degree angle is transmitted, and the remainder reflected. Instead of a metallic coating, a dielectric optical coating may be used. Such mirrors are commonly used as output couplers in laser construction. A half-silvered mirror used in photography is often called a pellicle mirror. Depending on the coating that is being used, reflection/transmission ratios may differ in function of the wavelength.

Attribute Specifiction
Material BK7, Fused Silica, optical glass
Dimension Tolerance (mm) ±0.05
Thickness Tolerance (mm) ±0.05
Surface Quality 10/5
Parallelism <1arc min
Flatness (per 25mm@633nm) <λ/10
T/R 50/50±5%, for random polarization 
T=(Ts+Tp)/2, R=(Rs+Rp)/2
Surface1 Single wavelength partial reflectance
Surface2: AR-coating


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AIO ( incidence angle: 45 degree)

S1: Single wavelength partial reflectance

S2: AR-coating

Standard Coating wavelength:

Narrow Band: -----488, 532, 632.8, 650, 808, 850, 980, 1064, 1310, 1550 nm

Broadband:----------- 450-650, 650-900, 900-1200, 1200-1550, 1500-1610 nm