Notch Filter
Notch Filters are precision optical filters designed to reject specific wavelength bands. They transmit surrounding wavelengths with minimal attenuation. Using advanced dielectric coating technology, notch filters provide high optical density blocking at the target rejection band. This ensures excellent transmission outside the blocked range. Chenyu Optics manufactures notch filters in optical glass and fused silica, with custom rejection wavelengths, bandwidths and coating options.
Notch Filter Overview
Notch Filters are precision optical filters designed to block specific wavelength bands. At the same time, they transmit surrounding wavelengths with minimal attenuation.
Using advanced dielectric coating technology, notch filters provide high optical density rejection at the target wavelength range. They also maintain high transmission outside the blocked band. As a result, engineers use them in laser suppression, Raman spectroscopy, fluorescence imaging, optical sensing and precision measurement systems.
In addition, Chenyu Optics supports custom notch filter manufacturing according to customer drawings. This includes custom substrate materials, dimensions, rejection wavelengths, bandwidths and coating designs for prototype and repeat production.
Key Advantages of Notch Filter
Laser Suppression & Raman Spectroscopy Systems
Notch filters are widely used for laser line rejection in laser suppression systems, Raman spectroscopy equipment, fluorescence imaging and precision measurement instruments.
Typical Specifications of Notch Filter
| Material Options | Optical Glass, BK7, Fused Silica |
|---|---|
| Coating Type | Dielectric notch coating |
| Optical Function | Wavelength rejection / laser line blocking |
| Rejection Wavelength | Customizable |
| Rejection Bandwidth | Customizable |
| Transmission | High transmission outside the rejection band |
| Blocking | High optical density at target wavelength |
| Surface Quality | High precision optical finish |
Spectral Transmission Curve (Typical)
Why Choose Chenyu Optics for Notch Filter
Chenyu Optics focuses on drawing-based precision filter manufacturing for laser suppression, spectroscopy, fluorescence imaging and industrial optical systems. We support prototype verification, small-batch production and repeat manufacturing for non-standard notch filters.
Manufacturing Capability for Notch Filter
Precision Polishing
High surface quality processing for stable filter performance.
Dielectric Coating
High performance dielectric notch coating for precise rejection wavelength and bandwidth control.
Inspection & Packaging
Strict quality control on rejection wavelength, bandwidth and blocking, with clean protective packaging before shipment.
Custom Notch Filter Options
Rejection vs. Bandpass Filter Comparison
| Filter Type | Typical FWHM | Peak Transmission | Blocking (OD) | Typical Applications |
|---|---|---|---|---|
| Notch Filter | < 1 – 10 nm (rejection band) | >90% (outside band) | OD4 – OD6+ | Laser suppression, Raman spectroscopy |
| Laser Line Filter | < 1 – 5 nm | >90% | OD4 – OD6+ | Laser measurement, Raman spectroscopy |
| Bandpass Filter | 10 – 50 nm | >90% | OD4 – OD6+ | Machine vision, instrumentation |
| Edge Filter | N/A (edge-based) | >90% | OD4 – OD6+ | Fluorescence, spectroscopy |
Applications of Notch Filter
Laser Suppression Systems
Rejection of specific laser wavelengths in optical setups.
Raman Spectroscopy Equipment
Rejection of the excitation laser line for Raman signal detection.
Fluorescence Imaging Systems
Blocking of excitation light while transmitting emission signal.
Optical Sensing Systems
Rejection of interfering wavelengths in optical sensor design.
Precision Measurement Instruments
Wavelength rejection for accurate spectral measurement.
Machine Vision Systems
Rejection of unwanted spectral lines in inspection equipment.
Notch Filter FAQ
What is a notch filter used for?
A notch filter blocks a specific wavelength band while transmitting surrounding light with minimal attenuation.
What parameters define a notch filter?
Key parameters include rejection wavelength, rejection bandwidth, peak transmission outside the band, optical density blocking, and incident angle.
How is a notch filter different from a bandpass filter?
A notch filter rejects a narrow wavelength band while transmitting everything else, the functional opposite of a bandpass filter, which transmits only a selected band.
Can notch filters be customized for different rejection wavelengths?
Yes. Filters can be customized for UV, visible, and near-infrared rejection wavelengths.
Does incident angle affect notch filter performance?
Yes. The rejection wavelength can shift with incident angle, so coating design should match the optical setup.
What information should I provide for a quotation?
Please provide rejection wavelength, rejection bandwidth, substrate material, dimensions, angle of incidence, quantity and drawing if available.
Where can I learn more about notch filter design?
Additional information on notch filter design can be found from Edmund Optics.
Related Products for Notch Filter
Need Custom Notch Filters?
Send us your rejection wavelength, bandwidth, substrate, dimensions, coating requirements and quantity. Chenyu Optics will review the optical and mechanical specifications and provide a suitable notch filter manufacturing suggestion.