Hyperspectral Imaging Lens 1.0μm-2.5μm SWIR Case Study
Shanghai Optics recently collaborated with an industry leading spectrometer manufacturer to design and optimize a Hyperspectral imaging SWIR lens for spectroscopic diagnostics equipment. The system is optimized for Extended SWIR (eSWIR) imaging, capturing critical data between 1.0 μm and 2.5 μm.
The 1.0 μm – 2.5 μm range is technically Extended SWIR. Standard SWIR stops at 1.7 μm.
Spectroscopes are scientific instruments typically used in applications where a spectrum of light needs to be separated into individual spectral lines. The common components of a spectroscope include a light source, monochromator, detector and any relating HW/SW used for processing.
Material Selection and Coating Technology
Due to the broadband requirements of the application in the shortwave infrared spectrum, our optical design team carefully chose the appropriate glass materials and coating formula to ensure that the required wavelengths would be transmissible throughout the 1 μm-2.5 μm region. Also, too mitigate any chromatic aberration or secondary spectrum within the optical design, special materials were chosen to meet the strict demands of the SWIR lens application.
Structural Analysis
Unlike standard SWIR lenses limited to a 1.7 μm cutoff, we utilize specialized infrared-grade materials and Chalcogenide glasses to ensure superior transmission and color correction up to 2.5 μm.
ZnSe and ZnS are generally considered MWIR/LWIR materials. While they work in SWIR, they are rarely the “better” choice for a high-resolution imaging lens in the 1.0 μm – 2.5 μm range because they have very high refractive indices, leading to higher Fresnel reflections and potential chromatic issues when used alone.
The working wavelength of this lens is between 1.0μm-2.5μm which it can be widely used for many applications.
The MTF curves demonstrate exceptional contrast and clarity, maintaining high modulation transfer at frequencies optimized for the latest InGaAs sensor pixel pitches. MTF is greater than 0.25 at 100lp/mm and MTF is greater than 0.3 at 80lp/mm. Compare to other SWIR Lens, the spatial resolution of our lens is very good and can obtain ideal imaging quality when using in the spectrometer.
Core Advantages
- High precision mechanical design for extremely fine focusing
- Fully refractive optical design
- Fast F/2.4 aperture for high light-gathering efficiency
- Fully color-corrected design to eliminate chromatic aberrations across the entire spectral range
- Ultra broadband AR coating
- Outstanding spectrum/spatial resolution
- Low scattering /low stray light with noise reduction
Typical Applications
- Remote Sensing for Measurement and Analysis
- Quality Control for:
- Food Safety
- Pharmaceutical
- LCD Displays
- Photovoltaics and Solar Panels
- Waste Recycling and Sorting
