close
Choose Your Site
Global
Social Media
As a core variant of interference-type filters, our bandpass filters leverage advanced thin-film coating technology—combining alternating layers of high-refractive-index (e.g., HfO₂) and low-refractive-index (e.g., SiO₂) materials—to achieve exceptional spectral control. Unlike broadband filters that transmit wide wavelength ranges, they provide targeted transmission within a defined wavelength window, ensuring minimal signal interference and maximum detection accuracy across diverse scenarios, from semiconductor wafer inspection to environmental gas analysis. With the growing demand for high-resolution optical systems in fields like gene sequencing and quantum sensing, our bandpass filters are engineered to meet strict performance standards, including sub-nanometer wavelength stability and low thermal drift.
Wavelength Range: Covering 175–3200nm+, our bandpass filters support applications from deep ultraviolet (DUV) semiconductor lithography (175–250nm) to mid-infrared (MIR) chemical detection (2500–3200nm) .
Bandwidth Control: Available with 1nm to 100nm+ bandwidth options, customizable to specific experimental requirements. Narrow bandwidths (1–10nm) are ideal for high-resolution Raman spectroscopy (e.g., 532nm excitation with 2nm bandwidth for molecular fingerprinting), while wider ranges (50–100nm+) suit multi-fluorescence imaging systems (e.g., flow cytometers with 80nm bandwidth for FITC/Cy3 dual-channel detection) .
Peak Transmission: Customizable peak transmission profiles (up to >95% for visible wavelengths) ensure optimal signal-to-noise ratio for critical measurements, such as low-concentration analyte detection in liquid chromatography-mass spectrometry (LC-MS) .
Surface Quality: Meticulously polished to 20-10 or 10-5 scratch-dig standards (per MIL-PRF-13830B) for reduced light scatter—critical in astronomy applications where stray light can distort celestial object imaging .
Parallelism: Maintains <3 arcsec parallelism to minimize beam deviation in high-precision optical setups, such as laser interferometers used for optical component metrology .
Dimensional Options: Available in 12.5–100mm diameter configurations, with custom square or rectangular formats (e.g., 20×20mm for integrated microfluidic chips) to fit standard and custom optical systems. Thickness options (0.5–5mm) accommodate different mounting requirements, from compact handheld devices to large-scale industrial detectors .
Nanoscience: Enables precise wavelength selection in nanoparticle characterization systems, such as dynamic light scattering (DLS) instruments, where 633nm bandpass filters isolate laser light from particle scattering signals .
Bioscience: Critical for fluorescence microscopy (e.g., confocal microscopy) where specific fluorophore emissions (e.g., GFP at 520nm, RFP at 605nm) require isolation from excitation light. Also used in polymerase chain reaction (PCR) machines to detect fluorescently labeled DNA amplicons .
Gas Detection: Used in oil & gas environmental monitoring systems to identify specific gas signatures—for example, 1550nm bandpass filters detect methane (CH₄) absorption lines, while 2300nm filters target carbon dioxide (CO₂) .
Laser Guidance: Ensures accurate wavelength transmission in laser-based targeting systems (e.g., military rangefinders) by blocking ambient light and isolating the 1064nm laser line, improving target acquisition accuracy in harsh environments .
Laser Surgery: Filters stray wavelengths to protect tissue during laser procedures—for instance, in ophthalmic LASIK surgery, 193nm excimer laser systems use bandpass filters to block longer-wavelength UV radiation that could damage the cornea .
Medical Imaging: Integrates into optical coherence tomography (OCT) devices, where 1310nm bandpass filters enable deep-tissue imaging (up to 2mm in skin) by transmitting near-infrared light while blocking visible light scatter .
Q: What determines the bandwidth of a bandpass filter?
A: Bandwidth is defined by the full width at half-maximum (FWHM) of the transmission curve, ranging from 1nm to 100nm+ in our products. The number of thin-film layers, layer thickness uniformity, and substrate material all influence bandwidth—more layers (50–100) create narrower bandwidths, while fewer layers (20–30) result in wider ranges. Narrow bandwidths (1–10nm) suit high-resolution spectroscopy, while wider ranges (50–100nm+) are ideal for imaging applications where multiple fluorophores need simultaneous detection .
Q: Can bandpass filters be customized for specific wavelengths?
A: Yes, we offer custom peak transmission options tailored to unique experimental needs, covering the entire 175–3200nm+ spectrum. Customization includes adjusting peak wavelength (e.g., 850nm for near-infrared facial recognition systems), bandwidth (e.g., 5nm for quantum dot fluorescence detection), and edge steepness (e.g., <5nm transition between blocked and transmitted regions for high-contrast imaging) .
Q: How does surface quality affect performance?
A: Our 20-10 or 10-5 surface quality standards minimize light scattering, ensuring >90% transmission efficiency in the passband while reducing background noise. For example, a 10-5 surface (10 scratch width, 5 scratch density) scatters <0.1% of incident light, making it suitable for low-light applications like single-molecule fluorescence spectroscopy, where even small scatter can obscure weak signals. In contrast, a 20-10 surface is sufficient for industrial inspection systems with higher signal intensity .
Q: Are these filters suitable for high-power laser systems?
A: While optimized for spectral precision, our standard bandpass filters handle moderate laser power (up to 1W/cm² for continuous-wave lasers at 532nm). For high-energy applications (e.g., pulsed lasers with >1J/cm² energy density), inquire about our enhanced coating options—such as HfO₂/SiO₂ multi-layer coatings with laser-induced damage thresholds (LIDT) of >5J/cm² @ 1064nm, 10ns pulses—designed to prevent coating degradation or substrate damage .
