M4904 Broadband Notch Filter
Sharp notch rejection with superior passband transmission for maximum light throughput.
- Notch centre: 532.8 nm
- Notch width (FWHM): 157.2 nm
- Notch depth: OD ≥ 3.2 (T < 0.07%)
- Passband transmittance: ≥ 90.3% T (outside notch region)
- Edge steepness: ~19.5 nm (90 → 10 % per edge)
- Passband recovery: Within 11 nm of notch edges
- AOI: 0° (normal incidence); custom angles available
- Construction: Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick
- Custom options: Centre tuning, notch width adjustment, multi-notch designs, rapid prototypes
Learn more
M4904 Hybrid delivers Notch centre 532.8 nm, Notch width (FWHM) 157.2 nm, and Notch depth OD ≥ 3.2 (T < 0.07%).
The hard-oxide coating is built for repeated handling, heat, and cleaning.
Best suited for:
High-efficiency fluorescence detection, photomultiplier-based instruments, solar simulator systems, and applications requiring maximum light collection.
Description
The M4904 provides balanced spectral performance with a narrow 157 nm notch and outstanding transmission characteristics. Operating with only 0.07 % depth at 518 nm while blocking 466-592 nm, this filter achieves 91.1 % transmission in the blue passband and 94.2 % in the red-NIR region. Peak transmission of 95.3 % makes it an excellent choice for applications where signal preservation is critical alongside demanding rejection specifications.
Key Advantages
- Exceptionally Low Notch Depth - 0.07 % transmission at 518 nm provides superior rejection of green laser lines and green fluorescence
- Narrow Notch Design - 157 nm blocking width preserves passband width while achieving deep spectral isolation
- Durable Ion-Assisted Coatings - Hard-oxide multilayer construction withstands thermal cycling and aggressive cleaning protocols
- Extended Substrate Options - Round, square, and custom free-form geometries on Borofloat, soda-lime, Schott D263 T, and Corning Eagle XG
- High Red Transmission - 94.2 % across 618-780 nm maximizes signal detection in NIR-sensitive applications
Typical Applications
- Raman Spectroscopy - Suppresses 532 nm Rayleigh scatter while transmitting anti-Stokes Raman signals across separated bands
- Laser-Based Biomedical Imaging - Enables 532 nm laser excitation with red fluorescence and NIR autofluorescence collection
- Photomultiplier Tube Filtering - Protects sensitive detectors from green stray light in PMT-based fluorescence systems
- Hyperspectral Imaging - Creates distinct spectral bins for computational spectral unmixing algorithms
- Environmental Monitoring - Measures blue-excited and red-emitted chlorophyll fluorescence in water quality assessment
Prototype delivery within 2-3 weeks; full production runs support both research and OEM integration requirements.
FAQ
M4904 FAQ
What is M4904 and what is it used for?
M4904 is a 454/611 nm Notch Filter. The M4904 provides balanced spectral performance with a narrow 157 nm notch and outstanding transmission characteristics. Operating with only 0.07 % depth at 518 nm while blocking 466-592 nm, this filter achieves 91.1 % transmission in the blue passband and 94.2 % in the red-NIR region. Common uses include Raman Spectroscopy, Laser-Based Biomedical Imaging, Photomultiplier Tube Filtering, and Hyperspectral Imaging.
What are the key optical specs of M4904?
Key published specs for M4904 include Notch centre: 532.8 nm; Notch width (FWHM): 157.2 nm; Notch depth: OD ≥ 3.2 (T < 0.07%); Passband transmittance: ≥ 90.3% T (outside notch region); Edge steepness: ~19.5 nm (90 → 10 % per edge).
What applications is M4904 best suited for?
M4904 is commonly used for Raman Spectroscopy, Laser-Based Biomedical Imaging, Photomultiplier Tube Filtering, and Hyperspectral Imaging. Raman Spectroscopy - Suppresses 532 nm Rayleigh scatter while transmitting anti-Stokes Raman signals across separated bands.
Can M4904 be customized for size, substrate, or coating requirements?
KUPO lists the construction for M4904 as Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick. Published custom options include Centre tuning, notch width adjustment, multi-notch designs, rapid prototypes. Extended Substrate Options - Round, square, and custom free-form geometries on Borofloat, soda-lime, Schott D263 T, and Corning Eagle XG.
What should I know about angle of incidence and durability for M4904?
The published angle of incidence for M4904 is 0° (normal incidence); custom angles available. The hard-oxide coating is built for repeated handling, heat, and cleaning.
