News | November 10, 2025

Breakthrough Dual Purpose AOTF Hyperspectral Imagers

Sparks, MD - A powerful and unique AOTF based instrument that combines both, hyperspectral imager and spectropolarimeter into one package. Brimrose new hyperspectral spectropolarimeter imager (HSPI) can easily switch from a hyperspectral imager to a spectropolarimeter and back again. There are significant advantages to having both in one instrument. For example, if one image is hazy, the other may provide significantly more information by adjusting the polarimetry.

Brimrose new series of AOTF-based HSPI offers significantly larger number of bands that can be used in image post processing analysis with more accurate information. When incorporated with waveplate/retarders, the imager system can be easily configured to measure all six polarization states needed for Stokes vector measurement on each pixel. The instrument can be used to develop ground based, airborne, or space-flight instrument with similar configurations, without pushbroom scan.

The AOTF device is controlled electronically, which provides correct acoustic frequency driving the transducer as RF frequencies. AOTF HSI have several advantages over traditional pushbroom HSI. Traditional HSI requires careful handling and frequent calibration. They also suffer lower scan speed and lower reliability. An AOTF is an all solid-state tunable filter with no moving parts and is therefore immune to orientation changes or even severe mechanical shock and vibrations. Moreover, the AOTF is a high throughput and high-speed programmable device capable of accessing wavelengths at rates up to 16 kHz, making it an excellent tool for in-situ spectroscopy. Some of the key advantages of the AOTF HSI technology are summarized below:

  • Polarization Selection – AOTF can be used as analyzer for linear polarized light.
  • Fast speed. up to 16,000 wavelengths per sec • High optical throughput efficiency. As a result of a high diffraction efficiency (up to 90%).
  • Large field of view (FOV) angle up to ~ 13 degrees
  • Increasing reliability and ruggedness. As a result of the AOTF being a compact solid-state device (typically 1 to 5 cm3) without any mechanical moving parts, it is insensitive to mechanical vibration / shock, and can be battery powered. Temperature change induced shift of wavelength can be virtually eliminated by adjusting the acoustic frequency accordingly and thus can operate over extreme temperature ranges.

The HSPI is available in both the VIS and SWIR ranges and can be customized per customer requirements in terms of camera frame rate or spatial resolution. For more information, contact Jan Kasprzak at 410-472-7070 or jank@brimrose.com.