DURIP: Broadband photothermal common-path interferometry for research in high-power optical materials and devices
Abstract
Publicly releasable project summary:We propose to acquire a photothermal common-path interferometry (PCI) system with multiple watt-level pump laser sources from the visible to the long-wave infrared and a cryostat for temperature control of the sample. PCI is a relatively uncommon interferometric technique, in which the optical absorption of a sample (e.g., thin film, suspended membrane, or optical metasurface) can be measured even for samples that have such low absorption coefficients that they cannot be reliably measured using spectroscopic ellipsometry and other conventional techniques. In PCI, a watt-level pump laser illuminates the sample, and the small fraction of the pump that is absorbed results in thermal lensing which can then be measured interferometrically using a probe beam.The new PCI system will function synergistically with existing capabilities in PI Kats s laboratory and shared facilities atthe University of Wisconsin-Madison, including variable-angle spectroscopicellipsometry and Fourier transform micro-spectroscopy over a broad wavelength range. This capability will enable measurements of engineered optical materials under development in Kats s laboratory under ONR Award N00014-20-1-2297, including measurements of loss-loss regions of perovskite chalcogenides recently demonstrated to have world-record infrared anisotropy and phase-transition materials currently being engineered for nonlinear optics and sensor protection in the mid-wave infrared (MWIR) and long-wave infrared (LWIR) spectral ranges. The capability will also enable new research of relevance to the DoD, including the development of a continuous-spectrum PCI spectroscopy technique to enable the most fine-grained optical models for transparent materials, and the selection, characterization, and engineering of low-loss materials and structures for laser-light sails for propulsion of light spacecraft that can carry sensors and do not use chemical or other propellant.The PCI instrument will directly impact research-based education in DoD-relevant fields of high-power laser systems and precision optical measurements of optical materials, including in semiconductors and quantum materials, which are areas of national defense and economic priority. The instrument will be immediately accessible by 12 PhD students and postdocs in the PI s laboratory, and graduate students and other trainees from 4 other research groups at the University of Wisconsin-Madison which actively use PI Kats s laband instrumentation. The instrument will also benefit research-based education for 17 research groups which are active or recent collaborators of PI Kats in the US and abroad.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 08, 2024
- Source ID
- N000142412182
Entities
People
- Mikhail A Kats
Organizations
- Office of Naval Research
- United States Navy
- University of Wisconsin System