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Optical limiter based on epsilon-near-zero materials

Award Information
Agency: Department of Defense
Branch: Army
Contract: W58RGZ-21-C-0032
Agency Tracking Number: A2-8600
Amount: $342,075.84
Phase: Phase II
Program: SBIR
Solicitation Topic Code: A18-131
Solicitation Number: 18.3
Solicitation Year: 2018
Award Year: 2021
Award Start Date (Proposal Award Date): 2021-03-12
Award End Date (Contract End Date): 2022-06-29
Small Business Information
310 S Harrington St
Raleigh, NC 27603-1111
United States
DUNS: 080132824
HUBZone Owned: No
Woman Owned: No
Socially and Economically Disadvantaged: No
Principal Investigator
 Christopher Shelton
 (503) 740-7565
Business Contact
 Edward Sachet
Phone: (919) 816-2191
Research Institution

The emerging class of epsilon-near-zero (ENZ) materials are promising candidates for non-linear optical (NLO) applications like optical limiting. In ENZ materials, large NLO effects, particularly in the infrared, have been demonstrated at much lower optical fluxes than have been shown in traditional NLO materials. The effect has been linked to the unique electric field concentration that occurs in ENZ materials near their zero permittivity frequency. In addition to producing extraordinary NLO effects, many groups have demonstrated that the property change is an ultrafast (fs) phenomena. These shared properties, ultrafast response and low threshold for NLO change, lend themselves to use in optical limiting applications, where ultrashort pulsed lasers are becoming an evermore concerning threat. During a recent Phase 1 feasibility study, Third Floor Materials demonstrated that the NLO effect in ENZ materials designed to operate in the MWIR, could be effectively leveraged by combining them with optical antenna structures. The antenna structure allows coupling to the ENZ mode from free-space and concentrates electric field intensity within the ENZ material further augmenting the NLO effect. Some of these hybrid meta-material/ENZ structures showed better than 2 orders of magnitude limiting at a 3 µm wavelength. To extend the usefulness of the hybrid antenna/ENZ approach, Third Floor Materials will pursue two principle objectives in the Phase 2 follow on program; an effort to broaden the response of the ENZ limiting structure across the entire MWIR (3-5 µm) and a parallel thrust designed to increase ‘off-state’ transmission. Similar to the Phase 1 study, our team will use real, measured ENZ material properties to develop a NLO FDTD model of an ENZ limiting system – and build a prototype for Army AvMC evaluation. We believe that the proposed approach will significantly expand Army understanding of ENZ materials and providing a compelling early use case in the form of an ultra-fast optical limiting solution.

* Information listed above is at the time of submission. *

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