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 Features
The filters exploit the interference effect of reflected light generated at the interface of a thin film to transmit desired wavelength regions. Compared with absorptive colored glass filter and gelatine filters, etc., interference filters have extremely good contrast with very narrow or sharply defined transmission bands.
Applications
Applicable to colorimeters, flame spectrometers, monochromators, laser, optical communication, optical data storage, etc. |
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Effect of Angle of Incidence
When a filter is tilted with respect to the optical axis of the incident light, its transmission band shifts toward the shorter wavelength. At angles of incidence larger than 20 degrees, the transmission band splits into two separate peaks, because the P-component (parallel to the plane of incidence) and the S-component (perpendicular to the plane of incidence) are shifted by different amounts.
Operating Temperature
The MIF type or DIF type should be used for operation for long periods up to 50deg C. It can also be used up to 80deg C for short periods. The interference filter may suffer deterioration such as change of filter characteristics depending on the operating environmental conditions. When ordering, inform us of the environmental conditions.
Required information
When you place an order, please state the required CWL, Half value width and filter size. Out of band blocking should also be specified. This can be achieved by the combination of multi-layer cut filter and color glass. So, please designate the cut off region matching to your needs corresponding to sensor sensitivity.
Specifications of an interference filter
Tmax : Maximum transmittance
Lambda 0 : Center wavelength
Lambda 0 = (Lambda 1+Lambda 2)/2
Delta 1/2 = Lambda 2-Lambda 1 : Half-width
A standard product
Metal-dielection interference filters : MIF=S/W type
All-dielectric interference filters : DIF-A/B/C type, DIF-BPF-1/2/3/4/5 type
Plasma ion coat band-pass filter : PIF-BPF type
Infrared interference filter : IR-BPF 0/1/2/3/4 type
Cut regions of all-dielectric interference filters and plasma ion coat band-pass filters
An interference filter is made up of a combination of several filters as shown in the figure below. Normally, a standard cut region is used unless specified otherwise. The cut region is generally determined according to the sensitivity region of the sensor. It is possible to further widen the cut region, but this reduces transmittance slightly due to loss caused by the cut filter.
MIF-S type
Available wavelength
range [nm]
|
Maximum
Transmittance
[%]
|
Half-width
[nm]
|
Center wavelength
Tolerance [nm]
|
Standard
dimensions [mm] |
Diameter
|
Square
|
| 376-405 |
25-45 |
</=18 |
+/-3 |
15
20
30
40
50 |
50 x 50 |
| 406-475 |
30-45 |
</=13 |
+/-3 |
| 476-705 |
30-47 |
</=13 |
+/-3 |
| 706-955 |
30-45 |
</=20 |
+/-4 |
| 956-1195 |
28-45 |
</=35 |
+/-4 |
| 1196-1500 |
28-45 |
</=40 |
+/-5 |
[Features]
This filter comprises a three-layer structure of semitransparent metal film, transparent dielectric film and semitransparent metal film formed on a glass or quartz plate with a protective cemented glass or quartz plate on it. When the optical thickness of these two kinds of metal film is half lambda of a specific wavelength or an integer multiple of such, the filter passes mostly that wavelength and blocks out other wavelengths.
MIF-W type
Available wavelength
range [nm]
|
Maximum
Transmittance
[%]
|
Half-width
[nm]
|
Center wavelength
Tolerance [nm]
|
Standard
dimensions [mm] |
Diameter
|
Square
|
| 210-230 |
10-25 |
</=20 |
+/-3 |
15
20
30
40
50 |
50 x 50 |
| 231-260 |
15-25 |
</=20 |
+/-3 |
| 261-315 |
15-25 |
</=25 |
+/-3 |
| 316-375 |
15-25 |
</=30 |
+/-3 |
| 376-395 |
30-40 |
</=25 |
+/-3 |
| 396-455 |
35-48 |
</=20 |
+/-3 |
| 456-595 |
35-48 |
</=15 |
+/-3 |
| 596-700 |
35-48 |
</=20 |
+/-3 |
[Features]
The W-type interference filter comprises 5 layers made of two S-type interference filter combination, and has the optical characteristics of narrow BPF with sharp cut-on and cut-off. Though W-type interference filter is comparatively brighter than S-type one, which means it has a broader half value width, it offers a sharper edged optical line and a greater contrast between pass band and rejection band.
Available
wavelength
range [nm]
|
Standard
cut region
|
A type |
B type |
C type |
Maxi-
mum
Trans-
mittance
[%]
|
Appro-
ximate
ratio of
half width
to center
wave-
length
[%]
|
Maxi-
mum
Trans-
mittance
[%]
|
Appro-
ximate
ratio of
half width
to center
wave-
length
[%]
|
Maxi-
mum
Trans-
mittance
[%]
|
Appro-
ximate
ratio of
half width
to center
wave-
length
[%]
|
| 420-429 |
Cut up to
720nm |
>/=35 |
0.7 |
- |
- |
- |
- |
| 430-450 |
>/=40 |
0.7 |
>/=35 |
0.3 |
>/=35 |
0.25 |
| 451-499 |
>/=65 |
0.7 |
>/=50 |
0.32 |
>/=40 |
0.21 |
| 500-549 |
>/=70 |
0.75 |
>/=65 |
0.4 |
>/=40 |
0.2 |
| 550-599 |
>/=75 |
0.9 |
>/=70 |
0.4 |
>/=40 |
0.18 |
| 600-699 |
>/=75 |
0.95 |
>/=70 |
0.5 |
>/=40 |
0.16 |
| 700-799 |
Cut up to
(Center
wavelength
/0.85) |
>/=75 |
1 |
>/=70 |
0.55 |
- |
- |
| 800-899 |
>/=75 |
1 |
>/=70 |
0.55 |
- |
- |
| 900-999 |
>/=75 |
1 |
>/=70 |
0.6 |
- |
- |
| 1000-1099 |
>/=75 |
1 |
>/=70 |
0.6 |
- |
- |
| 1100-1199 |
>/=75 |
1.1 |
>/=70 |
0.6 |
- |
- |
| 1200-1299 |
>/=75 |
1.1 |
>/=70 |
0.6 |
- |
- |
| 1300-1399 |
>/=75 |
1.1 |
>/=70 |
0.6 |
- |
- |
| 1400-1499 |
>/=75 |
1.1 |
>/=70 |
0.6 |
- |
- |
| 1500-1599 |
>/=75 |
1.1 |
>/=70 |
0.65 |
- |
- |
| 1600-2000 |
>/=75 |
1.1 |
>/=60 |
0.65 |
- |
- |
[Features]
This filter consists of dielectric multilayer films instead of MIF-S type semitransparent metal films. The Dielectric multilayer film has a higher degree of transparency, and so this filter has a narrower half-width than the MIF-S type and has higher transmittance, and can thereby sharply define the wavelength of transmitted light. All dielectric interference filters are classified as type A, B or C depending on the half-width.
Available
wavelength
range [nm]
|
Standard
cut
region
|
BPF-1 type |
BPF-2 type |
BPF-3 type |
BPF-4 type |
BPF-5 type |
Maxi-
mum
Trans-
mittance
[%]
|
Appro-
ximate
ratio of
half
width
to
center
wave-
length
[%]
|
Maxi-
mum
Trans-
mittance
[%]
|
Appro-
ximate
ratio of
half
width
to
center
wave-
length
[%]
|
Maxi-
mum
Trans-
mittance
[%]
|
Appro-
ximate
ratio of
half
width
to
center
wave-
length
[%]
|
Maxi-
mum
Trans-
mittance
[%]
|
Appro-
ximate
ratio of
half
width
to
center
wave-
length
[%]
|
Maxi-
mum
Trans-
mittance
[%]
|
Appro-
ximate
ratio of
half
width
to
center
wave-
length
[%]
|
| 420-429 |
Cut
up to
720nm |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
| 430-450 |
>/=55 |
1.2 |
>/=55 |
2.3 |
>/=55 |
3.6 |
>/=55 |
8 |
>/=55 |
13 |
| 451-499 |
>/=60 |
1.2 |
>/=60 |
2.3 |
>/=60 |
4.2 |
>/=60 |
8 |
>/=60 |
14 |
| 500-549 |
>/=70 |
1.5 |
>/=70 |
2.3 |
>/=70 |
4.5 |
>/=70 |
8 |
>/=70 |
15 |
| 550-599 |
>/=70 |
1.5 |
>/=70 |
2.5 |
>/=70 |
4.7 |
>/=70 |
8 |
>/=70 |
15 |
| 600-699 |
>/=70 |
1.7 |
>/=70 |
2.5 |
>/=70 |
4.7 |
>/=70 |
8 |
>/=70 |
15 |
| 700-799 |
>/=75 |
1.8 |
>/=75 |
2.6 |
>/=75 |
4.8 |
>/=75 |
9 |
>/=75 |
16 |
| 800-899 |
Cut
up to
(Center
wave-
length
/0.85) |
>/=75 |
1.8 |
>/=75 |
2.7 |
>/=75 |
4.8 |
>/=75 |
9 |
>/=75 |
16 |
| 900-999 |
>/=75 |
1.8 |
>/=75 |
2.9 |
>/=75 |
5 |
>/=75 |
9 |
>/=75 |
16 |
| 1000-1099 |
>/=75 |
1.8 |
>/=75 |
3 |
>/=75 |
5 |
>/=75 |
9 |
>/=75 |
16 |
| 1100-1199 |
>/=75 |
2 |
>/=75 |
3 |
>/=75 |
5 |
>/=75 |
9.2 |
- |
- |
| 1200-1299 |
>/=75 |
2 |
>/=75 |
3 |
>/=75 |
5.3 |
>/=75 |
9.2 |
- |
- |
| 1300-1399 |
>/=75 |
2 |
>/=75 |
3 |
>/=75 |
5.3 |
>/=75 |
9.3 |
- |
- |
| 1400-1499 |
>/=75 |
2 |
>/=75 |
3 |
>/=75 |
5.3 |
>/=75 |
9.7 |
- |
- |
| 1500-1599 |
>/=75 |
2 |
>/=75 |
3 |
>/=75 |
5.3 |
>/=75 |
9.7 |
- |
- |
| 1600-2000 |
>/=65 |
2 |
>/=65 |
3 |
>/=65 |
5.5 |
- |
- |
- |
- |
[Features]
This filter consists of dielectric multilayer films instead of MIF-W type semitransparent metal films. Since this filter provides a wider half-width than the DIF-type A/B/C, it is possible to clealy and selectively transmit a relatively wide wavelength. All dielectric interference filters are classified as type 1 to type 5 depending on the ratio of the half bandwidth to the center wavelength.
Center
wavelength [nm]
|
Tolerance [nm]
|
Maximum
Transmittance [%]
|
Half-width [nm]
|
Standard dimensions
Diameter [mm]
|
| 254 |
+/-4.0 |
>/=40 |
20+/-5 |
30
40
50 |
| 313 |
+/-4.0 |
>/=70 |
18+/-2 |
| 365 |
+/-4.0 |
>/=85 |
19+/-2 |
| 405 |
+/-4.0 |
>/=85 |
20+/-2 |
| 436 |
+/-4.0 |
>/=85 |
25+/-2 |
[Features]
The PIF-BPF is a filter manufactured using the plasma ion process and features exellent durability and environmental resistance.
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