แนวคิดหลัก
A custom-designed wide-band camera lens is proposed to replace the commercial lenses currently used in the MISTRAL imager-spectrograph, providing improved throughput, resolution, and spectral coverage.
บทคัดย่อ
The MISTRAL instrument is a visible and near-infrared imager and spectrograph developed for the 1.93m telescope at l'Observatoire de Haute Provence. It currently uses interchangeable commercial lenses to cover the full spectral range, which has limitations in terms of throughput, vignetting, and spectral coverage.
The proposed custom lens design aims to address these issues. It uses a 5-lens configuration with two aspheric surfaces to cover the 400-1000nm waveband with a focal length of 100mm and f/# = 2. The design is optimized for both imaging and low-resolution spectroscopy modes.
Key performance improvements include:
- Improved throughput of 79-98% across the 400-1000nm range, compared to the commercial lenses.
- Uniform image quality across the field of view, with 84% of the energy concentrated within ±1 pixel.
- Spectral resolving power up to R = 1675 in the near-infrared, a 57% improvement over the commercial lenses.
- The design is shown to be technologically feasible, with tolerances that can be practically achieved.
Overall, the custom lens design provides significant advantages over the current commercial lenses used in the MISTRAL instrument, enabling enhanced scientific capabilities in both imaging and spectroscopic observations.
สถิติ
The custom lens design has a focal length of 100mm and f/# = 2.
The throughput varies from 79% to 98% across the 400-1000nm waveband with a commercial AR coating.
The spectral resolving power reaches up to R = 1675 in the near-infrared, a 57% improvement over the commercial lenses.
คำพูด
"The proposed design has the focal length of 100mm with f/# = 2 and consists of 5 lenses with 2 aspheres. It is capable to work in spectroscopy or direct imaging mode with the spectral resolving power up to R590−1675 or energy concentration of 84% within ±1pix."
"The throughput varies from 79to98% in the main band of 400-1000 nm with a commercial AR coating and could be yet improved with a custom one."