Laser system for studying classical optical entanglement in space and time
Abstract
We propose to acquire a wavelength-tunable pulsed laser system to study a new class of pulsed optical fields that we denote space-time (ST) wave packets. These are pulsed laser beams whose spatial and temporal degrees of freedom are inextricably intertwined, in contrast to traditional optical fields where these degrees of freedom are typically independent of each other. As a result of the spatio-temporal structure inculcated into the optical field, ST wave packets exhibit novel and unexpected behaviors upon free propagation, and interact with optical materials and photonic devices in unique ways. Using the proposed laser system, we will synthesize ST wave packets inwhich each spatial frequency (underlying the spatial profile of the beam) will be preciselyassociated with a different wavelength (underlying the temporal pulse linewidth).Using this proposed tunable pulsed laser system and associated optical characterizationtools, we intend to carry out research in two areas in support of multiple funded projects supported by the Office of Naval Research (ONR). In the first research area, we will utilize the broad spectral tunabiliy of this laser system to extend our current experimental efforts on the synthesis of ST wave packets into the visible and near-infrared spectral regimes.In the second research area, we will investigate a new class of broadband nonlinear optical limiters that operate in reflection mode. Such devices can be instrumental in protecting the eyes of military personnel or sensitive sensors. Rather than exploiting bulk nonlinear optical materials as is the common approach to constructing a limiter, our design makes use of resonant field enhancements in a planar optical cavity containing a thin layer of a nonlinear material having a large two-photon absorption coefficient. The device operates as a reflective limiter: at low power levels, light that resonates with the cavity is transmitted, whereas at high fluence rates of incident radiation the light is reflected back and not absorbed, thus avoiding damage to the device. Such adevice benefits from the resonant field enhancement in the cavity, but suffers from the concomitant limitation of narrowband operation as an unescapable consequence of the resonance linewidth. Indeed, larger resonant field enhancements result in narrower operational linewidths, which is a consequence of the inverse relationship between the cavity quality factor and the cavity-photon lifetime. We have recently demonstrated that ST wave packets allow circumventing this fundamental limitation. Sculpting the spatio-temporal spectrum of a pulsed optical field can yield omni-resonant ST wave packets: pulsed beams than can resonate with a planar cavity eben if the pulse bandwidth far exceeds the resonant linewidth. The proposed laser system, by virtue of itswavelength tunablity and its high pulse energy, will be employed to study the nonlinear omni-resonant regime. Besides the fundamental optical science to be explored, research in this area is expected to yield broadband reflective optical limiters capable of rejecting a high-power laser at any wavelength within its omni-resonant spectrum.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 09, 2021
- Source ID
- N000142112639
Entities
People
- Ayman F Abouraddy
Organizations
- Office of Naval Research
- United States Navy
- University of Central Florida Board of Trustees