Bandpass Filter

Often referred to as long wave pass (LWP) and short wave pass (SWP) filters, these sharp-cut edge filters are distinguished by their high rate of transition between their region of reflection and transmission. This high rate of transition makes them an excellent choice as emission filters in fluorescence applications, and as order sorting filters in photometry. They are also very useful as stray light or trim filters, to eliminate any unwanted near band radiation. All LWP/SWP filters are constructed of hard, durable first-surface dielectric coatings, and will withstand the normal cleaning and handling associated with any high-quality optical component. Their film construction is essentially a modified quarter-wave stack, using interference effects rather than absorption to isolate their spectral bands. Unlike filter glass, which is not sensitive to wavelength shift with angle, these filters will shift shorter in wavelength with an increase in their angle of incidence. This feature can be useful in applications where it may be desirable to fine tune the 50% cut-on, or cut-off wavelength. All standard edge filters are available in 50nm increments from 400nm to 1000nm. Custom edge filters are available and will be quoted upon request.

General Specifications
Size Tolerance: +0.0, - 0.2mm
Thickness: 2.0mm to 8.0mm
Minimum Clear Aperture: 90% of O.D.
Substrate Material: Glass
Flatness: 2λ per 25mm
Parallelism: 3 arc minutes
Surface Quality: 80/50
Cut-on and cut-off slopes: 6%
Cut-on and cut-off tolerance: ±10nm
Cut on , Cut off : Wavelength of 50% Peak transmission
Blocking :
Long wave pass : UV to 0.85λ c Cut on
Block Optical Density : Typically 0.1% , O.D 3

VISIBLE AND NEAR INFRARED LONG WAVE PASS FILTERS
Cut-on (λc) (nm)
T range (nm)
Tave%
φ12.5mm
φ25.4mm
:φ50.0mm
Part No.
Part No.
Part No.
400
410-2200
80%
LF1040
LF2040
LF3040
450
460-2200
80%
LF1045
LF2045
LF3045
500
510-2200
80%
LF1050
LF2050
LF3050
550
560-2200
80%
LF1055
LF2055
LF3055
600
610-2200
80%
LF1060
LF2060
LF3060
650
660-2200
80%
LF1065
LF2065
LF3065
700
715-2200
80%
LF1070
LF2070
LF3070
750
765-2200
80%
LF1075
LF2075
LF3075
800
815-2200
80%
LF1080
LF2080
LF3080
850
865-2200
80%
LF1085
LF2085
LF3085
900
920-2200
80%
LF1090
LF2090
LF3090
950
970-2200
80%
LF1095
LF2095
LF3095
1000
1020-2200
80%
LF1100
LF2100
LF3100
Please refer to the Glossary and Technology for more information about waveplates.
Other sizes and coatings are available upon request.