1230nm Optical Filter – 40nm Bandwidth Wide Band Blocking To 3000nm Overview

This 1230nm optical filter (FWHM) has a 40nm center wavelength of 1230nm and a half-bandwidth of 40nm. It offers high transmittance in the 1210-1250nm range and provides a wide bandwidth cutoff to 3000nm outside the passband. It effectively suppresses background stray light in near-infrared, short-wave infrared, and long-wave infrared, reducing the impact of SWIR long-wave background and thermal noise on the detector. It is commonly used in applications such as laser ranging, SWIR imaging, silicon wafer inspection, moisture/gas sensing, and spectral analysis.

Coligh is a manufacturer of near-infrared and short-wave infrared optical filters. We support the entire production process from film system design, coating, cutting, cleaning, and inspection. We customize the center wavelength, half-bandwidth, substrate, and cutoff depth according to the customer’s laser wavelength, detector type, ambient temperature, and dimensions.

1230nm Optical Filter – 40nm Bandwidth Wide Band Blocking To 3000nm Product Features

It possesses the following core characteristics:

• Suitable for near-infrared and short-wave infrared bands, with a center wavelength of 1230nm and a FWHM of 40nm.
• Transmittance greater than 95% in the 1210-1250nm range.
  Broadband cutoff up to 3000nm, capable of suppressing long-wave background radiation in SWIR.
• Cutoff depth OD4-OD6. The rigid dielectric film exhibits high environmental stability and wear resistance.

1230nm Optical Filter – 40nm Bandwidth Wide Band Blocking To 3000nm Spectrum

1230nm / 40nm Narrow Bandpass Filter with IR Blocking up to 3000nm Specifcation

• CWL：1230+/-5nm
• FWHM: 40+/-5nm
• Tp>=95%
• Blocking: 400-3000nm@OD>=4

Coligh Customize Capability Of Narrow Bandpass Filter

As an experienced optical filter manufacturer, we offer highly flexible customization to meet a wide range of optical and photonic applications. Two independently specified transmission bands can be designed and optimized according to your application, including center wavelength, bandwidth (FWHM), peak transmittance, blocking range, substrate, dimensions, AOI, and laser damage threshold.

1230nm / 40nm Narrow Bandpass Filter with IR Blocking up to 3000nm Applications

1230nm Laser Ranging and LiDAR

When operating outdoors, 1230nm laser ranging and lidar systems are exposed to sunlight, ambient infrared radiation, and long-wave background light. Narrow-band filters allow only laser echoes near 1230nm to pass through, suppressing other bands and improving the signal-to-noise ratio. The FWHM 40nm filter strikes a balance between transmittance and interference resistance, adapting well to temperature and angle variations, and improving ranging accuracy, detection range, and resistance to background light.

SWIR Short-Wave Infrared Imaging

SWIR imaging can penetrate certain materials and identify moisture and internal structures, but ambient light and thermal radiation reduce contrast. A 1230nm bandpass filter isolates the target wavelength and suppresses long-wave background light down to 3000nm. This improves image contrast and defect detection rate, reduces background noise, and is suitable for plastic sorting, food inspection, agricultural product sorting, penetration testing, and industrial non-destructive testing.

Moisture, Humidity, and Gas Sensing

Some substances exhibit absorption or characteristic responses around 1230 nm, which can be used for moisture, humidity, or specific gas sensing. Narrow-band filters isolate the target wavelength and suppress interference from other bands. This improves imaging depth and signal purity, reduces background noise, and is suitable for scientific research, biomedicine, and spectroscopic detection.