FSR-KG1 Heat Absorbing Glass Filter

The FSR-KG1 Heat Absorbing Glass Filter is a 25.4 mm diameter infrared (IR) cut-off filter made of Schott KG1filter glass. Heat absorbing glass filters reduce the heat transmitted through an optical system. They have high transmission in the visible wavelength region and absorb in the IR wavelength region, making them also useful as a shortpass filter. These absorption filters are precision polished for demanding research or OEM applications.

This filter is extremely susceptible to high humidity. The filter will absorb moisture, and discoloration may happen. Please store this in a low humidity environment.

Specifications

Technical Specs

Type

Heat Absorbing Filter
Material

Schott KG1 or equivalent
Center Wavelength

VIS
Angle of Incidence

0°
Size

Ø25.4 mm
Size Tolerance

±0.3 mm
Thickness

2.0 to 3.0 mm, typical
Surface Flatness

≤1λ at 632.8 nm over the clear aperture

Surface Quality

60-40 scratch-dig
Damage Threshold

30 W/cm² CW, Typical
Wedge

≤3 arc min
Clear Aperture

central ≥ 80% of diameter
Chamfers

Up to 1 mm face width
Chamfers Angle Tolerance

45° ±15°
Cleaning

See How to Clean Optics

Type

Heat Absorbing Filter
Material

Schott KG1 or equivalent
Center Wavelength

VIS
Angle of Incidence

0°
Size

Ø25.4 mm
Size Tolerance

±0.3 mm
Thickness

2.0 to 3.0 mm, typical
Surface Flatness

≤1λ at 632.8 nm over the clear aperture

Surface Quality

60-40 scratch-dig
Damage Threshold

30 W/cm² CW, Typical
Wedge

≤3 arc min
Clear Aperture

central ≥ 80% of diameter
Chamfers

Up to 1 mm face width
Chamfers Angle Tolerance

45° ±15°
Cleaning

See How to Clean Optics

Resources & Downloads

2D / 3D CAD Software

Download CAD Files

Drawings And Cad

FBR-NDXX-S (62 kB, PDF)

Other

FSR-KG1 RoHS Certificate (705.5 kB, PDF)

Related Products

Similar

Description	Compatibility	Avail.	Price
FSR-OD400 Neutral Density Filter, Absorptive, 25.4 mm, 4.0 OD at 546.1 nm	UNIVERSAL	Show	$40
10HMR-0 Hot Mirror, 25.4 mm, 0° AOI, 420-690 nm Transmittance	UNIVERSAL	In Stock	$59
FSQ-KG3 Heat Absorbing Glass Filter, 50.8 x 50.8 mm, IR Cut-off, KG-3 Glass	UNIVERSAL	In Stock	$81
20HMS-0 Hot Mirror, 50.8 x 50.8 mm, 0° AOI, 420-690 nm Transmittance	UNIVERSAL	In Stock	$79

Compatible

	Compare	Description	Compatibility	Drawings, CAD & Specs	Avail.	Price
		FH-1R Optical Filter Mount, Stackable, 1.0 in. Diameter Optics	UNIVERSAL		In Stock	$42
		FH-1S Optical Filter Holder, Drop-in, 25.4 mm Optics	UNIVERSAL		In Stock	$87

Heat Absorbing Glass Filter, 25.4 mm Diameter, IR Cut-off, KG-1 Glass