OLPF : Optical Low Pass Filter
(The following spec. is for example, we can design and produce customer need. Please contact us)
(check substrate type, thickness, dimension, shap.)
Optical low pass filter (OLPF)
Apply: Optical low pass filter (OLPF) is used in high end (high resolution) digital camera sensor to eliminate interference influence (Moire pattern) by crystalline birefringency. An OLPF can cut off the undesired high spatial frequency when the sensor resulting the image. IR cut-off function is often incorporated into OLPF as well. Some use absorptive blue glass + AR , or direct coating an IR cut thin films layers .
Moire Pattern In High resolution image
|
OLPF Optical Low Pass Filters
|
The OLPF Spectrum is similar to IR Cut Filter or Day and Night Filter.
The Spectrum function generally need to match CCD resolution (270K/380K(410K)) and its characteristic.
Spectrum And Specification Example:
380K IR600 (Triplex Plates)
Specification
No |
Material |
Single Thickness |
θ |
ψ |
Flatness(NR) |
Parallelism(mm) |
Remark |
±1° |
±1° |
1 |
0°Double
Refraction plate |
1.08± 0.05 |
45° |
0° |
5 |
0.005 |
AR coating |
2 |
Infrared absorbing glass |
1.60± 0.05 |
NA |
NA |
7 |
0.005 |
C-500S(Hoya)
Or equivalent |
3 |
45°Double Refraction plate |
0.75± 0.05 |
45° |
45° |
5 |
0.005 |
AR coating |
Spectrum
Wavelength |
Transmittance |
Wavelength |
Transmittance |
400nm |
T> 80% |
700nm |
T<5% |
430~580nm |
T> 88% |
800-1000nm |
T<2% |
600+/-10nm |
T=50% |
1000-1100nm |
. |
380K IR645 (Single Plate)
Specification
No |
Material |
Single Thickness |
θ |
ψ |
Flatness(NR) |
Parallelism(mm) |
Remark |
±1° |
±1° |
1 |
0°Double
Refraction plate |
1.08± 0.05 |
45° |
0° |
5 |
0.005 |
AR coating
IR coating |
Spectrum
Wavelength |
Transmittance |
Wavelength |
Transmittance |
400nm |
T> 87.2% |
700nm |
T<1.1% |
450~600nm |
T > 91.3% |
750~1000nm |
T<1.9% |
645+/-10nm |
T=50% |
1100nm |
T<1.7% |
380K Day and Night 645/850 (Single Plate)
Specification
No |
Material |
Single Thickness |
θ |
ψ |
Flatness(NR) |
Parallelism(mm) |
Remark |
±1° |
±1° |
1 |
0°Double
Refraction plate |
1.08± 0.05 |
45° |
0° |
5 |
0.005 |
AR coating
IR coating |
Spectrum
Wavelength |
Transmittance |
Wavelength |
Transmittance |
400nm |
T> 60% |
800~920nm |
T=50%.BW>60nm |
420~600nm |
Tave> 90% Tmin>80% |
850+/-10nm |
C.W@T=50% |
645+/-10nm |
T=50% |
C.W+/-5 |
Tave=85% |
700 |
T<0.7% |
950~1100 |
T<7.8% |
| 380K Day and Night 645/850 (Double Plates) |
 |
Specification
No |
Material |
Single Thickness |
θ |
ψ |
Flatness(NR) |
Parallelism(mm) |
Remark |
±1° |
±1° |
1 |
45°Double
Refraction plate |
0.75± 0.05 |
45° |
45° |
5 |
0.005 |
AR coating
IR coating |
2 |
0°Double
Refraction plate |
1.08± 0.05 |
45° |
0° |
5 |
0.005 |
Spectrum
Wavelength |
Transmittance |
Wavelength |
Transmittance |
395+/-10nm |
T= 50% |
800~920nm |
T=50%.BW>60nm |
420~600nm |
Tave>90%,Tim>85% |
850+18/-15nm |
C.W@T=50% |
645+/-10nm |
T=50% |
C.W+/-5 |
Tave=85% |
700 |
T<5% |
950~1100 |
T<40% |
270K IR 620 (Double Plates)
Specification
No |
Material |
Single Thickness |
θ |
ψ |
Flatness(NR) |
Parallelism(mm) |
Remark |
±1° |
±1° |
1 |
0°Double
Refraction plate |
1.63± 0.05 |
45 |
0 |
5 |
0.005 |
AR Coating |
2 |
Infrared absorbing glass |
1.00+/-0.05 |
NA |
NA |
5 |
0.005 |
AR Coating |
Spectrum
Wavelength |
Transmittance |
Wavelength |
Transmittance |
400nm |
T > 80% |
700 nm |
T < 15% |
430~580nm |
T > 88% |
800~1000nm |
T < 2% |
620+/-10nm |
T = 50% |
1000~1100nm |
T < 10% |
270K IR 645 (Single Plate)
Specification
No |
Material |
Single Thickness |
θ |
ψ |
Flatness(NR) |
Parallelism(mm) |
Remark |
±1° |
±1° |
1 |
0°Double
Refraction plate |
1.63± 0.05 |
45 |
0 |
5 |
0.005 |
IR 645 Coating |
Spectrum
Wavelength |
Transmittance |
Wavelength |
Transmittance |
400nm |
T>80% |
700nm |
T<5% |
430~600nm |
T>88% |
700-1000nm |
T<2% |
645+/-10nm |
T=50% |
1100nm |
T<5% |
270K Day and Night 645/850 (Single Plate)
Specification
No |
Material |
Single Thickness |
θ |
ψ |
Flatness(NR) |
Parallelism(mm) |
Remark |
±1° |
±1° |
1 |
0°Double
Refraction plate |
1.63± 0.05 |
45 |
0 |
5 |
0.005 |
IR645/850 Coating |
Spectrum
Wavelength |
Transmittance |
Wavelength |
Transmittance |
420nm |
T > 90% |
835+-/10 nm |
T = 50% |
430~600nm |
T > 90% |
850+/-35nm |
T >80% |
645+/-10nm |
T = 50% |
895+/-10nm |
T =50% |
650~800nm |
T<5% |
950~1100nm |
T<5% |
|
