Linear Variable
Interference Filters

Barr precision optics& thin film coatings

Materion Barr Precision Optics & Thin Film Coatings is a leading
manufacturer and supplier of precision optical filters, hybrid circuits, flexible thin films
and custom thin film coating services. We offer coating solutions for manufacturers in
the defense, commercial, space, science, astronomy and thermal imaging markets.

Linear Variable Interference Filters
Materion designs and manufactures both edge-type and bandpasstype variable filters to customer specifications. The key featureof these devices is that spectral properties vary with position in aprescribed way along the lengthwise direction of the filter.
Materion has capabilities to manufacture variable filters within thespectral range from approximately 300nm in the ultraviolet toapproximately 10 microns in the far infrared.

Linear Variable Edge Filters
A Materion Linear Variable Edge Filter (LVEF) is comprised of aninterference filter coating on a glass or fused silica substratedeposited in such a way that the spectral position of the edge
varies linearly along the length of the filter.
Materion offers LVEF’s manufactured to customer spectral anddimensional specifications. These filters are made with durable
oxide coatings on glass or fused silica substrates. Linear Variable
Edge Filters are typically used in grating-based systems as ordersorting filters. The LVEF is often placed on the front window of adetector array to suppress second and third order effects.

Linear Dispersion for a LVEF (as expressed in nm/mm) is the slopeof wavelength (evaluated at the Half Power Wavelength) as afunction of linear position along the filter.
Linear Dispersion (nm/mm) =(HPWL 2 (nm) - HPWL 1(nm)) / (X2 (mm) - X1 (mm))
Where:
HPWL 1 = Half Power Wavelength # 1
HPWL 2 = Half Power Wavelength # 2
X1 = Linear position corresponding to HPWL 1
X2 = Linear position corresponding to HPWL 2

A typical value for Linear Dispersion in a Materion LVEF is
10 nm/mm.

Linear Variable Bandpass Filters
Materion has the capability to design and produce custom Linear
Variable Bandpass Filters (LVBF’s). Depending upon customer
requirements, effective blocking can be afforded over the second
and third order transmission ranges.
Typical LVBF

Typical Order Sorting LVEF

Linear Dispersion:
For a Materion LVBF the center wavelength position of the filter(expressed in nm) varies linearly with position (expressed in mm)along the length of the filter. Linear Dispersion for a LVBF (asexpressed in nm/mm) is the ratio of wavelength change (evaluatedat the Center Wavelength) divided by change in linear position along
the filter length.
Materion is a global advanced materials company, dedicated to providing solutions that enable our customers’ technologies and drive their growth. Our products include
precious and non-precious specialty metals, precision optical filters, inorganic chemicals and powders, specialty coatings, specialty-engineered beryllium alloys, beryllium
and beryllium composites, and engineered clad and plated metal systems. The Materion business is structured to enhance our ability to provide customers with innovative,
best total-cost solutions.
For precision optical coating products
2 Lyberty Way
Westford, MA 01886
Phone: +1 978.692.7513

for custom Thin film coating products
153 Industrial Way
Buellton, CA 93427
Phone: +1 805.688.4949

www.materion.com/barroptics

www.materion.com/barroptics

materion corporationwww.materion.com

BPO Linear Variable Filters Rev 02 03 ‘11