Advanced imaging spectrometer using freeform optics for enhanced spectral performance, compact design, and low distortion imaging
Institute Reference: 2-15140
Imaging spectrometers are essential for applications requiring high-resolution spectral analysis ranging from satellite imaging to food safety. Traditional spectrometers, such as the Offner-Chrisp and Czerny-Turner designs, utilize reflective optics to collect and disperse light across a detector array. However, achieving high spectral resolution, broader fields of view, and compact designs often involves trade-offs in performance and distortion. The development of freeform optical surfaces has introduced a new approach, enabling performance improvements without these compromises.
This technology presents an imaging spectrometer incorporating ϕ-polynomial freeform surfaces into primary, secondary, and tertiary optics—enhancing imaging performance. Unlike spherical or symmetric aspheric optics, freeform surfaces lack rotational symmetry, offering greater design flexibility. These surfaces can be defined using Zernike polynomials that include both radial and azimuthal components, enabling better aberration correction and optimal light dispersion.
By as quantified by spectral étendue, a metric accounting for slit length, numerical aperture, and angular dispersion, this spectrometer achieves broader spectral coverage and superior resolution. The system can maintain diffraction-limited performance over wider wavelength ranges and larger spatial fields of view than can be achieved with spherical or symmetric aspheric optics. Additionally, it offers reduced size and weight compared to traditional designs by shortening the optical path without sacrificing quality.
This innovative spectrometer achieves significantly improved spectral performance, offering a bandwidth that is up to three times broader than traditional systems. Its compact form factor reduces the spectrometer volume by as much as fivefold, enabling the development of miniaturized and lightweight devices ideal for portable or space-constrained applications. The design also minimizes key imaging distortions, such as spectral smile and spatial keystone, ensuring precise, high-quality imaging. With Zernike polynomial-based freeform surfaces, the technology provides enhanced customization, allowing for optimized performance tailored to specific use cases. Additionally, it offers a broader field of view by increasing slit length capacity while still maintaining diffraction-limited performance across all wavelengths.
This advanced spectrometer can support a range of critical applications across various industries. In satellite imaging and earth observation, it can capture detailed spectral data for environmental monitoring and mineral analysis, enabling better insights into ecosystems and natural resources. In the food safety and quality control sector, it can leverage hyperspectral imaging to analyze the chemical properties of food products, ensuring quality and safety standards are met. In aerospace and defense, its compact design can make it ideal for onboard spectral imaging in drones and aircraft, supporting reconnaissance and tactical operations. The technology can also play a role in medical imaging, where hyperspectral endoscopy can enable non-invasive diagnostics, offering a new dimension in healthcare. Additionally, in agriculture, it can provide essential crop health assessments and nutrient analysis through remote sensing, helping farmers optimize yields and manage resources more effectively.
The University of Rochester is open to exploring funded research collaborations, licensing agreements, and other partnership opportunities.