General Optics designs and manufactures a broad range of precision optical filters for laser, imaging, biomedical, industrial, and defense applications. Our filters are engineered to provide high transmission in passbands, deep blocking in rejection bands, and superior surface quality, with coatings tailored from UV (193 nm) to IR (14 μm).
Optical Window Manufacturing Limits
| Specifications | Size Range |
|---|---|
| Diameter / Thickness / Length / Width | Material dependent |
| Diameter / Thickness Tolerance | ± 0.1 mm / ± 0.01 mm |
| Surface Quality | 60-40 to 20-10 |
| Parallelism | ≤ 1 arc second |
| Surface Roughness | 0.5 nm |
| Clear Aperture | ≥ 95% |
Types of Optical Filters
- Dichroic Filters – Transmit passband, reflect rejection band; used in imaging and projection
- Bandpass Filters – Isolate narrow spectrum ranges for spectroscopy, microscopy, high-speed imaging
- Longpass & Shortpass Filters – Edge filters for spectral separation
- Notch Filters – Laser rejection for Raman spectroscopy, fluorescence, multiphoton microscopy
- Edge Filters – Harmonic reduction and scatter control
- Neutral Density (ND) Filters – Uniform attenuation across wide spectrum
- Infrared (IR) Filters – High IR transmission with strong out-of-band blocking for FLIR, security, environmental
- Ultraviolet (UV) Filters – UV blocking while maintaining high visible transmission
- Broadband Filters – High transmission across wide spectral bands
Materials & Coatings
- Materials: Fused Silica, Optical Glass, Color Glass, Display Glass, Low Expansion Glass
- Coatings: AR (UV–IR), HR, Broadband, DLC, custom multilayer dielectric coatings
- Shapes: Circular, Square, Rectangular, Elliptical
Applications
- Cinematography – Precision color correction, IR/UV control
- Clinical Chemistry – Spectral separation for analysis
- Laser Systems – Beam shaping, wavelength isolation, laser blocking
- Machine Vision & Imaging – Contrast enhancement, background suppression
General Optics Advantage
- Decades of expertise in precision grinding, polishing, and coating
- Advanced double-sided fabrication for exceptional parallelism
- In-house coating from DUV to IR, including High LIDT coatings
- Custom filters tailored to specific spectral ranges, shapes, and system integratio
Dichroic Filters (Longpass & Shortpass)
- Description: Multilayer dielectric coatings enable dichroic filters to transmit one region of the spectrum
(passband) while reflecting another (rejection band) - Capabilities: High extinction ratio, customizable edge steepness, and excellent angular stability;
available in plate and cube formats - Applications: Beam combination/separation in laser systems, color separation in digital projection,
CCD/CMOS imaging, fluorescence microscopy
Bandpass Filters
- Description: Precisely isolate narrow spectral bands while rejecting out-of-band wavelengths
- Capabilities: Narrowband (<1 nm FWHM) or broadband designs; blocking levels up to OD6;
optimized for high transmission and steep cutoffs - Applications: Spectroscopy, environmental sensing, chemical analysis, biomedical imaging,
fluorescence detection, astronomy
Longpass Filters
- Description: Pass long wavelengths while blocking shorter wavelengths, effectively cutting off UV/blue light
- Capabilities: Hard-coated dielectric multilayers with high transmission efficiency; edge cutoffs tunable to
customer specifications - Applications: IR imaging, night vision, laser separation, biomedical fluorescence emission filters
Shortpass Filters
- Description: Pass short wavelengths while blocking longer ones; complement longpass filters
for dual-band separation - Capabilities: Sharp edge slopes and high out-of-band blocking; available with AR coatings
to reduce reflections - Applications: UV imaging, fluorescence excitation, laser protection, optical inspection
Notch Filters
- Description: Block a narrow spectral band while transmitting all other wavelengths with high efficiency
- Capabilities: Narrow or multiple notch bands; blocking up to OD6 at laser wavelengths; designed for
high-power laser durability - Applications: Raman spectroscopy, fluorescence microscopy, laser rejection filters in scientific and
defense optics
Edge Filters
- Description: Spectral filters that define a sharp transmission cut between transmitted and blocked bands
- Capabilities: Available in longpass, shortpass, and bandpass edge designs; steep edge profiles <1%
transition bandwidth - Applications: Harmonic suppression, stray light reduction, beam diagnostics, analytical instruments
Neutral Density (ND) Filters
- Description: Provide uniform attenuation of optical power across a broad spectrum
- Capabilities: Optical density tolerance ±0.01 OD (uncoated), ±0.03 OD (coated); absorptive or
reflective ND types available - Applications: Laser power attenuation, imaging system calibration, detector protection, optical bench
Infrared (IR) Filters
- Description: Designed to transmit IR bands while blocking visible or UV wavelengths
- Capabilities: Custom narrowband or broadband IR filters; robust coatings for thermal stability and
harsh environments - Applications: FLIR systems, defense targeting optics, thermal imaging, remote sensing
Ultraviolet (UV) Filters
- Description: Block UV light while transmitting visible and IR regions, or vice versa depending on design
- Capabilities: High-durability coatings for deep-UV (193 nm) lasers; AR coatings minimize reflection losses
- Applications: UV-blocking safety optics, sterilization monitoring, lithography, biomedical fluorescence
systems
Broadband Filters
- Description: Provide wide spectral transmission while rejecting out-of-band light
- Capabilities: Exceptional transmission (>95%) across broad spectral regions (e.g., 400–700 nm,
700–1100 nm); customizable shapes and sizes - Applications: Multi-band imaging, astronomy, spectroscopy, broadband illumination systems
Filter Substrates
- Description: Precision-polished substrates produced for customer coating or system integration
- Capabilities: Double-sided polishing for superior parallelism; sizes up to Ø2050 mm available
- Materials: Fused silica, optical glass, low-expansion glass, display glass
Filter Shapes
- Standard: Circular, Square, Rectangular, Elliptical
- Custom: Complex geometries and assemblies available upon request
General Optics Advantage
- End-to-end manufacturing: design → polishing → coating → inspection
- Custom designs from UV (193 nm) to LWIR (14 μm)
- High durability coatings: AR, HR, Broadband, DLC, and laser-grade multilayers
- Proven expertise across semiconductor, biomedical, defense, aerospace, and industrial markets