HM-735 Hot Mirror & UV-IR Cut Filter

The HM-735 is the extended-visible flagship, pushing the 50 % cutoff to 734 nm-just 2 nm beyond HM-725-while delivering peak transmission of 95.4 % at 693 nm. Visible transmission spans 404-734 nm with blue at 86.6 %, green at 93.6 %, yellow at 94.6 %, and red at 94.7 %. The additional 2 nm of pass-through wavelength may seem marginal, but in applications where early NIR content matters (such as Si-based imaging), this extra bandwidth can be diagnostically significant. NIR blocking remains decisive: 23.4 % in 700-850 nm and 0.2 % above 850 nm.

Key Advantages

• Maximum visible-spectrum coverage - Extends to 734 nm, capturing near-complete red and early Si-sensitive NIR. Applications using silicon detectors benefit from this extended visible pass without thermal contamination.
• Consistent across visible spectrum - Blue, green, yellow, and red all exceed 86 % transmission, ensuring color-neutral imagery and faithful light delivery across all visible wavelengths.
• Hard-oxide ion-assisted coating - Robust optical coating withstands thermal stress, mechanical handling, and long-term exposure to high-intensity light sources without performance drift.
• Shallow UV leakage - UV transmission is 0.7 %, minimizing UV-induced noise in UV-sensitive detectors while preserving broad visible spectrum for full-color applications.
• Fully customizable format options - Available as round, square, or free-form blanks from 5 mm to 450 mm in diameter, thickness 0.21-3.8 mm, on Borofloat, soda-lime, Schott D263 T, or Corning Eagle XG.

Typical Applications

• Silicon-based camera systems - The extended 734 nm pass accommodates the Si detector peak sensitivity while blocking thermal IR, ideal for monochrome machine vision and scientific imaging.
• Broadband projection and lighting - Delivers maximum visible light flux while rejecting heat, suitable for high-brightness cinema, digital signage, and event lighting.
• Botanical and agricultural imaging - Captures near-infrared cues important for plant health assessment while maintaining visible spectrum fidelity for morphological analysis.
• Medical and dental imaging - Broad visible pass ensures diagnostic visibility of tissue while protecting sensitive endoscope and intraoral camera sensors from thermal radiation.
• Astronomy and space instrumentation - Extended visible coverage supports multi-wavelength astronomical observation with thermal rejection, beneficial in ground-based and space-borne instruments.

KUPO Optics delivers HM-735 filters in custom specifications with rapid turnaround, supporting both rapid prototyping and full production runs with your exact diameter, substrate, and thickness requirements.