Dichroic Filter
A dichroic filter is a thin optical filter crafted to transmit light in only one narrowly defined wavelength band while reflecting all other wavelengths. These optical filters are also known as thin-film or interference filters.
Dichroic filters are typically placed at a 45-degree angle to a light source. With this placement, blocked light is reflected at a 90-degree angle while specified wavelengths of light pass through the filter. If a light source is emitting white light, the light filtered through a filter of this type will seem to be highly saturated in color. A red filter, for instance, will transmit red wavelengths and reflect cyan. A green filter will transmit green and reflect magenta.
Longpass Dichroic Filters
| Substrate | Optical-Grade Float Glass (B270) |
| Transmitted Wavefront Error | λ/4@633nm |
| Parallelism | <30 arcsec |
| Surface Quality | 40-20 |
| Dimension Tolerance | +0.0/-0.1mm |
| Thickness | 2mm ±0.2mm |
| Cut-On Tolerance | ±10nm |
| Transmission | Tavg>90% |
| Reflection | Ravg>98% |
| Clear Aperture | >90% |
| Angle of Incidence | 45° |
| Cut-On Wavelength (nm) | Reflection Band (nm) | Transmission Band (nm) | Part Number | Request Quote |
|---|---|---|---|---|
| 425 | 370-400 | 440-1200 | SO-DIC-FIL-EE12C-0001 | Request a Quote |
| 450 | 370-430 | 465-1200 | SO-DIC-FIL-EE12C-0002 | Request a Quote |
| 500 | 370-480 | 515-1200 | SO-DIC-FIL-EE12C-0003 | Request a Quote |
| 550 | 385-520 | 565-1200 | SO-DIC-FIL-EE12C-0004 | Request a Quote |
| 600 | 460-570 | 620-1200 | SO-DIC-FIL-EE12C-0005 | Request a Quote |
| 650 | 495-615 | 670-1200 | SO-DIC-FIL-EE12C-0006 | Request a Quote |
| 700 | 535-665 | 720-1200 | SO-DIC-FIL-EE12C-0007 | Request a Quote |
| 750 | 565-715 | 770-1200 | SO-DIC-FIL-EE12C-0008 | Request a Quote |
| 800 | 600-760 | 820-1200 | SO-DIC-FIL-EE12C-0009 | Request a Quote |
| 850 | 635-810 | 870-1200 | SO-DIC-FIL-EE12C-0010 | Request a Quote |
Shortpass Dichroic Filters
| Substrate | Optical-Grade Float Glass (B270) |
| Transmitted Wavefront Error | λ/4@633nm |
| Parallelism | <30 arcsec |
| Surface Quality | 40-20 |
| Dimension Tolerance | +0.0/-0.1mm |
| Thickness | 2mm ±0.2mm |
| Cut-Off Tolerance | ±10nm |
| Transmission | Tavg>90% |
| Reflection | Ravg>98% |
| Clear Aperture | >90% |
| Angle of Incidence | 45° |
| Cut-Off Wavelength (nm) | Transmission Band (nm) | Reflection Band (nm) | Part Number | Request Quote |
|---|---|---|---|---|
| 450 | 370-430 | 470-545 | SO-DIC-FIL-EE12C-0011 | Request a Quote |
| 500 | 370-480 | 520-610 | SO-DIC-FIL-EE12C-0012 | Request a Quote |
| 550 | 400-530 | 575-725 | SO-DIC-FIL-EE12C-0013 | Request a Quote |
| 600 | 400-580 | 625-795 | SO-DIC-FIL-EE12C-0014 | Request a Quote |
| 650 | 400-630 | 675-850 | SO-DIC-FIL-EE12C-0015 | Request a Quote |
| 700 | 400-680 | 725-900 | SO-DIC-FIL-EE12C-0016 | Request a Quote |
| 750 | 400-725 | 800-990 | SO-DIC-FIL-EE12C-0017 | Request a Quote |
| 800 | 400-775 | 850-1050 | SO-DIC-FIL-EE12C-0018 | Request a Quote |
| 850 | 400-820 | 910-1110 | SO-DIC-FIL-EE12C-0019 | Request a Quote |
Dichroic Filters for Every Application
A dichroic filter is a thin optical filter crafted to transmit light in only one narrowly defined wavelength band while reflecting all other wavelengths. These optical filters are also known as thin-film or interference filters.
Dichroic filters are typically placed at a 45-degree angle to a light source. With this placement, blocked light is reflected at a 90-degree angle while specified wavelengths of light pass through the filter. If a light source is emitting white light, the light filtered through a filter of this type will seem to be highly saturated in color. A red filter, for instance, will transmit red wavelengths and reflect cyan. A green filter will transmit green and reflect magenta.
Shanghai Optics manufactures high-quality dichroic filters in longpass, shortpass, bandpass, bandblocking, and color correction types. These filters are carefully crafted to exact specifications, and since the color is intrinsically part of the filter, it will not bleach out. This gives our filters a much longer useful life than other conventional filters. Our dichroic filters also have a very high laser damage threshold.
Applications of Dichroic Filters
Dichroic filters play a vital role in various applications, including:
- LCD projectors
- Laser harmonic separation
- Fluorescence microscopy
- Multispectral imaging
- UV water purification monitoring
In systems requiring color separation, such as projectors or imaging devices, these filters effectively control RGB light. Variants like cold and hot mirrors, which are also based on dichroic principles, aid in high power heat management by reflecting visible light and allowing infrared light to pass or vice versa.
Types of Dichroic Filters
Longpass filters transmit all wavelengths above a given cut-on wavelength. Shortpass filters transmit wavelengths below a given cut-off. Bandpass filters transmit wavelengths over a narrow range, which may be specified.
Cold mirrors and hot mirrors are dichroic filters that remove unwanted heat from a system. When placed behind a light source, a cold mirror reflects all visible light forward while transmitting unwanted NIR light out at a 45° angle. A hot mirror will reflect NIR heat and transmit visible light out at a 0° angle.
Shanghai Optics Dichroic Filters
Our state-of-the-art dichroic filters feature a sharp transition from reflection to transmission. They also exhibit high transmission in the pass band. All of our filters are dielectric coated with IBS technology. We use hard coatings and no adhesives to improve the filters’ lifespan. These hard coatings provide good resistance to abrasion and temperature.
Our factory standard dichroic features are manufactured from UV-grade fused silica. They have an operating temperature from -45°C to about 85°C, and an angle of incidence of 45.0°. Our thickness tolerance limits are ±0.1 mm, and each of our filters has a clear aperture of at least 95%. Our standard dichroic filters are 25.2 mm by 35.6 mm by 1.1 mm.
We can also manufacture custom dichroic filters tailored to your specific needs. Our expert team will guide you through the design, prototyping, and production stages, ensuring that your custom filters are optimized for transmitted and reflected wavelengths and are designed for high-power optical systems. Please contact us to schedule a consultation or request a quote for your next project.
Key Features
- Sharp transition from reflection to transmission
- High transmission in pass band
- Hard coatings and no adhesives for long filter life span
- All dielectric coated with IBS technology
- Durable design for high-power applications
Factory Standard
- Angle of Incidence: 45.0°
- Shortpass Type Transmittance: Tabs>85%
- Dimensions: 25.2 mm x 35.6 mm x 1.1 mm
- Clear Aperture: >95%
- Operating Temperature: -45°C ~ 85°C
- Physical Durability: MIL-C-48497A
- Longpass Type Transmittance: Tabs>90%
- Reflection Band: Rabs>98%
- Thickness Tolerance: ±0.1 mm
- Transmitted Wavefront: 1/4λ RMS@633nm (per inch)
- Environmental Durability: MIL-STD-810F
- Substrate: UV Grade Fused Silica
Contact us for manufacturing limit or custom specifications.
Dichroic Longpass Filter
| Cut-off Wavelength(nm) | Reflection Band(nm) | Transmission Band(nm) | Size(mm) |
| 411 | 344-404 | 415-570 | 25.2*35.6*1.1 |
| 458 | 426-450 | 467-600 | 25.2*35.6*1.1 |
| 497 | 442-488 | 502-730 | 25.2*35.6*1.1 |
| 508 | 446-500 | 513-725 | 25.2*35.6*1.1 |
| 520 | 488-512 | 528-655 | 25.2*35.6*1.1 |
| 555 | 493-548 | 562-745 | 25.2*35.6*1.1 |
| 565 | 499-555 | 569-730 | 25.2*35.6*1.1 |
| 595 | 530-585 | 601-800 | 25.2*35.6*1.1 |
| 655 | 470-645 | 665-726 | 25.2*35.6*1.1 |
| 660 | 594-651 | 669-726 | 25.2*35.6*1.1 |
| 665 | 350-650 | 680-1100 | 25.2*35.6*1.1 |
| 669 | 350-660 | 677-800 | 25.2*35.6*1.1 |
| 735 | 350-720 | 750-1100 | 25.2*35.6*1.1 |
| 740 | 480-720 | 750-825 | 25.2*35.6*1.1 |
Dichroic Shortpass Filter
| Cut-off Wavelength(nm) | Transmission Band(nm) | Reflection Band(nm) | Size(mm) |
| 550 | 400-548 | 575-725 | 25.2*35.6*1.1 |
| 600 | 400-580 | 625-795 | 25.2*35.6*1.1 |
| 700 | 400-680 | 725-900 | 25.2*35.6*1.1 |
| 750 | 400-725 | 800-990 | 25.2*35.6*1.1 |
| 800 | 400-775 | 850-1050 | 25.2*35.6*1.1 |
| 850 | 400-820 | 910-1110 | 25.2*35.6*1.1 |
| 900 | 425-865 | 960-1170 | 25.2*35.6*1.1 |
| 950 | 450-910 | 1025-1235 | 25.2*35.6*1.1 |
| 1000 | 465-940 | 1085-1305 | 25.2*35.6*1.1 |
| 1050 | 485-1000 | 1130-1370 | 25.2*35.6*1.1 |
Need help?
We offer consultations and initial feasibility studies. If you have questions about limitations or lens capabilities we’re more than happy to work through your proposed custom components. As an unmatched custom optical provider, we’ll do everything that we can bring your vision to life.
