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IR-to-visible image upconverter under nonlinear crystal thermal gradient operation
Optics Express
|February 7, 2018
Summary
This study enhances infrared image up-converters using a thermal gradient in a periodically poled lithium niobate (PPLN) crystal. This method improves field-of-view tolerances for compact upconversion systems.
Area of Science:
- Optics and Photonics
- Nonlinear Optics
- Infrared Imaging
Background:
- Compact infrared image up-converters are crucial for various imaging applications.
- Periodically poled lithium niobate (PPLN) crystals are commonly used for frequency conversion.
- Enhancing the field-of-view (FOV) of up-converters is essential for broader imaging capabilities.
Purpose of the Study:
- To investigate the enhancement of the field-of-view (FOV) in compact infrared image up-converters.
- To explore the effect of a thermal gradient within a PPLN crystal on up-converter performance.
- To analyze the impact of crystal length and lens numerical aperture on FOV enhancement.
Main Methods:
- Utilizing a short PPLN crystal with high numerical aperture lenses for compact upconverter design.
- Implementing a thermal gradient across the PPLN crystal.
- Comparing performance with a constant temperature up-converter setup.
Main Results:
- A qualitative increase in both wavelength and angular tolerances was observed with the thermal gradient.
- The thermal gradient method demonstrated improved FOV compared to constant temperature conditions.
- Effective IR wavelength allocation is necessary to maximize the up-converted area.
Conclusions:
- A thermal gradient in a PPLN crystal effectively enhances the field-of-view of compact infrared image up-converters.
- The proposed method offers improved wavelength and angular tolerances, beneficial for practical applications.
- Careful IR wavelength allocation is crucial for optimizing the enhanced up-converted area.
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