HM-725 Visible-pass / infrared-attenuating filter

Visible-pass / infrared-attenuating filter (HM-725)

HM-725 is a visible-pass / infrared-attenuating filter. The main high-transmission region is approximately 410-724 nm. It can be considered when visible light is required and part of the longer-wavelength spectrum needs attenuation.

Optical performance

• Measured wavelength range: 300-1200 nm. Performance outside this measured interval is not established by this curve.
• Selected regions at or above 80% transmission: 410-724 nm. Approximate measured intervals.
• Selected regions at or below 5% transmission: 300-397 nm; 761-1200 nm. Measured sample intervals; confirm the required blocking for your order.
• Peak transmission: Approximately 95.4% at 691 nm. Peak wavelength is not the same as a defined centre wavelength.
• Average measured transmission, 425-710 nm: 94.062%. Calculated from the factory sample data.
• Average measured transmission, 780-1150 nm: 0.387%. Calculated from the factory sample data.
• Measured edge at 50% transmission: Approximately 732.0 nm. Interpolated absolute-transmission crossing, checked against the factory summary.
• Customization: We can customize stock and sample-book designs. Tell us the wavelength response, size and operating conditions you need.

These values come from the measured samples and help you choose a starting design. We will agree the final specification for your order. Custom versions have their own specifications and measured curves.

Applications to consider

• Visible-light camera systems: Evaluate attenuation of unwanted longer-wavelength light while retaining the visible signal. Check the entire detector sensitivity range, including any transmission recovery.
• Illumination optics: Consider spectral conditioning between a source and the illuminated object. Confirm the source-weighted transmitted power and how reflected or absorbed power is managed.
• Color-imaging development: Compare the visible response with the required camera color balance. Account for differences at the blue and red edges before choosing the optic.

Choosing this filter

• Check the full wavelength range of your light source, the wavelengths your detector responds to, and how much unwanted light you need to block. Use the full curve when choosing a filter; the product code and peak do not tell the whole story.
• Tell us the angle at which light reaches the filter and whether the beam is parallel or converging. For demanding rejection or high-power use, confirm the required blocking and power-handling specifications.

Custom options

Start with this stock or sample-book design, then tell us what you need to change. We can discuss the wavelength bands, transmission, blocking, angle, glass material, size and operating conditions with you, and agree a specification for your custom filter.