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Dual Bandpass Optical Filter

Precision filters that transmit two separate wavelength bands while blocking all other wavelengths.

A dual bandpass optical filter transmits two separately specified wavelength bands while blocking wavelengths outside both passbands. Chenyu Optics reviews the center wavelength, FWHM, required peak transmission, complete blocking range, optical density and angle of incidence for each custom design because achievable performance depends on wavelength, substrate, filter size and coating design.

2
Two Passbands
Independent Wavelength Selection
T
Specified Transmission
Per Passband
B
Defined Blocking
Between and Outside Bands
C
Custom Wavelengths
Independent Band Design
Dual Bandpass Optical Filter

Dual Bandpass Optical Filter Overview

Dual bandpass optical filters combine two independently specified transmission bands in one optical filter.

Each passband requires its own center wavelength, FWHM and peak transmission requirement. The blocking wavelength range and optical density must cover the wavelengths between the two passbands and the required regions on both sides.

Chenyu Optics supports custom dual bandpass filter manufacturing according to customer drawings, including custom substrate material, dimensions, center wavelength and bandwidth for each individual band for prototype and repeat production.

Key Advantages of Dual Bandpass Filter

2Simultaneous transmission of two independent wavelength bands.
TTransmission requirement specified separately for each passband.
BBlocking range defined between and outside both passbands.
SReduces the need for multiple single-band filters or filter wheels.
DDielectric coating design reviewed for the specified optical system.
CCustom center wavelengths and bandwidths per band.
Dual Bandpass Filter in Multi-Wavelength Fluorescence and Machine Vision Systems

Multi-Wavelength Fluorescence & Machine Vision Systems

Dual bandpass filters are widely used for simultaneous two-wavelength detection in fluorescence imaging systems, dual-wavelength laser setups and machine vision applications.

Dual Bandpass Optical Filter Specifications

ParameterBand 1Band 2
Center WavelengthAccording to customer requirementsAccording to customer requirements
FWHMAccording to customer requirementsAccording to customer requirements
Peak TransmissionSubject to technical confirmationSubject to technical confirmation
Blocking RangeSpecified between the two passbands and on both outer sidesSpecified between the two passbands and on both outer sides
Optical DensitySubject to technical confirmationSubject to technical confirmation
Final transmission, FWHM and blocking performance depend on wavelength, angle of incidence, substrate, filter size and coating design.

Spectral Transmission Curve (Typical)

Dual Bandpass Filter Spectral Transmission Curve
* Curve for reference only. Final performance is confirmed according to the agreed specifications and inspection conditions.

Why Choose Chenyu Optics for Dual Bandpass Filter

Chenyu Optics focuses on drawing-based precision filter manufacturing for fluorescence, laser, and machine vision systems. We support prototype verification, small-batch production and repeat manufacturing for non-standard dual bandpass filters.

Drawing review and tolerance evaluation
Prototype to production support
Custom substrate and dimension selection
Independent center wavelength and bandwidth design per band
Inspection report available upon request
Clean handling and protective optical packaging
Dual Bandpass Filter Manufacturing Workshop

Manufacturing Capability for Dual Bandpass Filter

Dual Bandpass Filter Precision Polishing

Precision Polishing

Surface and dimensional requirements are processed according to the approved drawing and inspection criteria.

Dual Bandpass Filter Dielectric Coating

Dielectric Coating Design

Coating requirements are reviewed according to both center wavelengths, bandwidths, transmission targets, blocking range and angle of incidence.

Dual Bandpass Filter Inspection and Packaging

Inspection & Packaging

Spectral and dimensional inspection follows the agreed requirements and available measurement range, followed by protective packaging.

Custom Dual Bandpass Filter Options

Custom Center Wavelength for Each Band
Custom Bandwidth (FWHM) for Each Band
Independent Blocking Range per Band
Custom Substrate Material
Custom Size and Shape
Peak Transmission Requirement per Band
Complete Blocking Range and OD Requirement
Angle-Optimized Coating Design
OEM & ODM Service
Prototype and Repeat Production Review

Bandpass Filter Type Comparison

Filter Type Typical FWHM Peak Transmission Blocking (OD) Typical Applications
Dual Bandpass Filter Specified independently for each band Subject to technical confirmation per band Subject to technical confirmation Multi-wavelength fluorescence, dual-laser systems
Narrow Bandpass Filter Custom specification available upon request Depends on wavelength and coating design Defined by required blocking range Laser line selection, fluorescence
Standard Bandpass Filter Custom specification available upon request Depends on wavelength and coating design Defined by required blocking range Machine vision, instrumentation
Wide Bandpass Filter Custom specification available upon request Depends on wavelength and coating design Defined by required blocking range Imaging, spectroscopy

Applications of Dual Bandpass Filter

FI

Multi-Wavelength Fluorescence Imaging

Simultaneous detection of two fluorophores in a single filter.

DL

Dual-Wavelength Laser Systems

Selective transmission of two independent laser lines.

MV

Machine Vision Systems

Multi-band spectral control for industrial inspection.

SP

Multiplexed Spectroscopy

Simultaneous measurement across two spectral bands.

OC

Optical Communication Systems

Dual-channel wavelength selection for communication links.

SR

Scientific Research Equipment

Precision dual-band filtering for research instruments.

Dual Bandpass Filter FAQ

What is the function of a dual bandpass filter?

A dual bandpass optical filter transmits two separately specified wavelength bands while blocking wavelengths outside both passbands.

Can the two passbands be positioned independently?

Yes. Each passband's center wavelength and bandwidth can be independently customized according to application requirements.

What are common uses of dual bandpass filters?

They are commonly used in multi-wavelength fluorescence imaging, dual-wavelength laser systems, and multiplexed spectroscopy.

Can dual bandpass filters be customized?

Yes. Custom center wavelengths, bandwidths, substrate materials, dimensions, and blocking ranges are available.

What information should I provide for a quotation?

Please provide both center wavelengths, both FWHM bandwidths, required transmission for each passband, the complete blocking range, optical density requirement, angle of incidence, filter dimensions and quantity.

Where can I learn more about bandpass filter design?

Additional information on bandpass filter design can be found from Edmund Optics.

Request a Custom Dual Bandpass Optical Filter Quote

Please provide both center wavelengths, both FWHM bandwidths, the required peak transmission for each passband, the complete blocking range, optical density requirement, angle of incidence, filter dimensions and quantity. These details are required to review the coating design and achievable performance.

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