LBTEK-Your Trusted Partner For Optoelectronic Experiments!

Product Description

Substrate Material: N-BK7
Working Wavelength: 350 nm-1100 nm
OD: 0.2, 0.3, 0.4, 0.5, 1.0, 2.0, 3.0, 4.0
Low Power Applications
Reflective Neutral Density Filters

LBTEK Reflective Neutral Density (ND) Filters are made of N-BK7 substrate with chrome-nickel-iron alloy coating, available in optical density (OD) ranges from 0.2 to 4.0. The sizes include Ø12.7 mm, Ø25.4 mm, and 50.8 mm×50.8 mm. LBTEK filters can be mounted on threaded tubes or coaxial mounting plates for use in coaxial systems, or installed in free space. LBTEK also offers customization services for other special sizes and optical density value attenuators. Please contact Technical Support for any requirements.

Attribute

Substrate MaterialN-BK7

Dimensional tolerance0.00/-0.25 mm

Operating Wavelength350 nm-1100 nm

Thickness2 mm

Clear Aperture>90% CA

Thickness tolerance±0.3 mm

OD（avg）0.2-4.0

Flatness (@633 nm)λ/2

Reflective Neutral Density Filter, Round, Unmounted

Substrate Material: N-BK7
Working Wavelength: 350 nm-1100 nm
Low Power Applications
Reflective Neutral Density Filter

LBTEK unmounted round reflective neutral density filters with optical density (OD) ranging from 0.2 to 4.0 are available in sizes of Ø12.7 mm and Ø25.4 mm. By depositing chrome-Inconel coating (single-sided) on N-BK7 substrates, these filters achieve a smooth OD curve across the 350 nm-1100 nm wavelength range. Although classified as reflective neutral density filters, the chrome-Inconel coating still absorbs a portion of the incident light. For optimal performance, it is recommended that light enters from the chrome-Inconel coated side. Be careful to avoid contact with this unprotected metal film, as contact may scratch the unprotected surface. It is recommended to use an air blower for cleaning.

An unmounted round reflective neutral density filter is mounted on the fixed lens mount.

Product Model	Diameter	OD（avg）	Substrate Material	Clear Aperture	Unit Price	Lead Time
NDFR05-40	Ø12.7 mm	4.0	N-BK7	＞90%	$29.81	7 weeks
NDFR05-30	Ø12.7 mm	3.0	N-BK7	＞90%	$29.81	7 weeks
NDFR05-20	Ø12.7 mm	2.0	N-BK7	＞90%	$29.81	7 weeks
NDFR05-10	Ø12.7 mm	1.0	N-BK7	＞90%	$29.81	7 weeks
NDFR05-05	Ø12.7 mm	0.5	N-BK7	＞90%	$24.71	7 weeks
NDFR05-04	Ø12.7 mm	0.4	N-BK7	＞90%	$24.71	7 weeks
NDFR05-03	Ø12.7 mm	0.3	N-BK7	＞90%	$24.71	7 weeks
NDFR05-02	Ø12.7 mm	0.2	N-BK7	＞90%	$24.71	7 weeks
NDFR10-40	Ø25.4 mm	4.0	N-BK7	>90%	$58.96	6 weeks
NDFR10-30	Ø25.4 mm	3.0	N-BK7	>90%	$58.96	6 weeks
NDFR10-20	Ø25.4 mm	2.0	N-BK7	>90%	$58.96	6 weeks
NDFR10-10	Ø25.4 mm	1.0	N-BK7	>90%	$46.02	6 weeks
NDFR10-05	Ø25.4 mm	0.5	N-BK7	>90%	$46.02	6 weeks
NDFR10-04	Ø25.4 mm	0.4	N-BK7	>90%	$46.02	6 weeks
NDFR10-03	Ø25.4 mm	0.3	N-BK7	>90%	$46.02	6 weeks
NDFR10-02	Ø25.4 mm	0.2	N-BK7	>90%	$46.02	6 weeks

Reflective Neutral Density Filter, Round, Mounted

Substrate Material: N-BK7
Working Wavelength: 350 nm-1100 nm
Low Power Applications
Reflective Neutral Density Filters
Mounted in mechanical housing, detachable

LBTEK round mounted reflective neutral density filters cover an optical density (OD) range of 0.2-4.0, with optical component sizes of Ø12.7 mm and Ø25.4 mm. By depositing chromium-nickel-iron alloy (single-sided) on an N-BK7 substrate, a smooth OD curve is achieved within the 350 nm-1100 nm wavelength range. Although classified as reflective neutral density filters, the chromium-nickel-iron alloy coating still absorbs some incident light. For optimal performance, it is recommended that incident light enters from the side with the chromium-nickel-iron alloy coating. Additionally, care should be taken to avoid contact with this unprotected metal coating, as touching may scratch the uncoated surface. When cleaning, the use of an air blower is advised. The MNDFR series reflective neutral density filters come mounted in detachable standard lens tubes, with the surface engraved with product model, working wavelength, OD value, and other parameters for easy identification for users.

A round reflective neutral density filter is mounted into adapter components via SM05 or SM1 threads.

Product Model	Diameter	OD（avg）	Substrate Material	Clear Aperture	Unit Price	Lead Time
MNDFR05-40	Ø12.7 mm	4.0	N-BK7	＞90%	$37.78	8 weeks
MNDFR05-30	Ø12.7 mm	3.0	N-BK7	＞90%	$37.78	8 weeks
MNDFR05-20	Ø12.7 mm	2.0	N-BK7	＞90%	$37.78	8 weeks
MNDFR05-10	Ø12.7 mm	1.0	N-BK7	＞90%	$37.78	8 weeks
MNDFR05-05	Ø12.7 mm	0.5	N-BK7	＞90%	$32.69	8 weeks
MNDFR05-04	Ø12.7 mm	0.4	N-BK7	＞90%	$32.69	8 weeks
MNDFR05-03	Ø12.7 mm	0.3	N-BK7	＞90%	$32.69	8 weeks
MNDFR05-02	Ø12.7 mm	0.2	N-BK7	＞90%	$32.69	8 weeks
MNDFR10-40	Ø25.4 mm	4.0	N-BK7	>90%	$68.12	6 weeks
MNDFR10-30	Ø25.4 mm	3.0	N-BK7	>90%	$68.12	6 weeks
MNDFR10-20	Ø25.4 mm	2.0	N-BK7	>90%	$68.12	6 weeks
MNDFR10-10	Ø25.4 mm	1.0	N-BK7	>90%	$58.96	6 weeks
MNDFR10-05	Ø25.4 mm	0.5	N-BK7	>90%	$58.96	6 weeks
MNDFR10-04	Ø25.4 mm	0.4	N-BK7	>90%	$58.96	6 weeks
MNDFR10-02	Ø25.4 mm	0.2	N-BK7	>90%	$58.96	6 weeks
MNDFR10-03	Ø25.4 mm	0.3	N-BK7	>90%	$58.96	6 weeks

Reflective Neutral Density Filter, Square, Unmounted

Substrate Material: N-BK7
Working Wavelength: 350 nm-1100 nm
Low Power Applications
Reflective Neutral Density Filter

LBTEK unmounted square reflective neutral density filters have an optical density (OD) range of 0.2-4.0 and dimensions of 50.8 mm × 50.8 mm. By depositing chrome Inconel alloy (single-sided) on N-BK7 substrates, a smooth OD curve is achieved across the 350 nm-1100 nm wavelength range. Although classified as reflective neutral density filters, the chrome Inconel coating still absorbs some incident light. For optimal performance, it is recommended that incident light enters from the chrome Inconel-coated side. Additionally, be careful to avoid contact with this unprotected metal film, as contact may scratch the unprotected surface. It is recommended to use an air blower for cleaning.

Unmounted square reflective neutral density filters on the fixed mounting bracket FHM1

Product Model	Size	OD（avg）	Substrate Material	Clear Aperture	Unit Price	Lead Time
NDFRS20-02	50.8 mm×50.8 mm	0.2	N-BK7	>45 mm×45 mm	$63.93	7 weeks
NDFRS20-03	50.8 mm×50.8 mm	0.3	N-BK7	>45 mm×45 mm	$63.93	7 weeks
NDFRS20-04	50.8 mm×50.8 mm	0.4	N-BK7	>45 mm×45 mm	$63.93	7 weeks
NDFRS20-05	50.8 mm×50.8 mm	0.5	N-BK7	>45 mm×45 mm	$63.93	7 weeks
NDFRS20-10	50.8 mm×50.8 mm	1.0	N-BK7	>45 mm×45 mm	$63.93	7 weeks
NDFRS20-20	50.8 mm×50.8 mm	2.0	N-BK7	>45 mm×45 mm	$79.62	7 weeks
NDFRS20-30	50.8 mm×50.8 mm	3.0	N-BK7	>45 mm×45 mm	$79.62	7 weeks
NDFRS20-40	50.8 mm×50.8 mm	4.0	N-BK7	>45 mm×45 mm	$79.62	7 weeks

Reflective Neutral Density (ND) Filters, Working Wavelength: 350 nm-1100 nm