DON27TZ02-NV015 TITLE: Photonic-Crystal Surface Emitting Lasers (PCSELS) in the Near-Infrared (NIR)

OUSW (R&E) CRITICAL TECHNOLOGY AREA(S): Scaled Directed Energy (SCADE)

COMPONENT TECHNOLOGY PRIORITY AREA(S): Advanced Materials;Directed Energy (DE);Quantum Science

PROJECTED CMMC LEVEL REQUIREMENT: Level 2 (Self)

OBJECTIVE: Develop and demonstrate scalable photonic-crystal surface-emitting laser (PCSEL) architectures that achieve higher output power while maintaining stable, single-mode, diffraction-limited beam quality using innovative photonic-crystal and optical metasurface designs in multi-aperture or integrated photonic configurations.

DESCRIPTION: The Navy seeks innovations in PCSELs that combine novel in-plane photonic crystal designs with out-of-plane epitaxial and gain structures to overcome the limitations of current approaches and produce the next generation of semiconductor laser technologies. Current PCSEL architectures face power-scaling limitations as device aperture increases because the mode margin between the desired fundamental mode and competing higher-order modes decreases, making stable, single-mode, diffraction operations increasingly difficult at higher powers. Capabilities that enable single mode, high power density, combinable lasers in the one-micron regime are the focus for any near-term transition. Concepts that maximize laser device area above previous limits, either by increasing the number of photons generated per unit area or increasing conversion efficiency, are potential options. Other potential approaches include reducing optical, electrical, and other losses – either with single devices, or through multi-device combinations. For example, stacking multiple gain regions vertically and horizontally, a successful technique used in vertical-cavity surface-emitting lasers ( VCSELs) arrays, may limit current PCSEL designs because of interactions between n++/p++ tunnel junctions in gain layers introducing unwanted absorption. Means to correct this issue through material modification might offer counteracting but beneficial additional total gain from a single device – especially when combined in the far field. Similarly, adding optical features as part of the photonic crystal to extend single-mode operation, especially those with higher conductivity material might reduce thermal distortions and lead to better performance even at the potential limits of vertical heat conduction. Further, adaptive metasurfacing of an existing PCSEL device (through micro- or nano-etching) might create new surface structures that modify laser output to enable more efficient photon conversion through the development of improved cavity properties.

The potential to demonstrate military utility by showing power scalability greater than single digit watts from an individual PSCEL, while maintaining single mode operation that result in combinable Solid State Lasers (SSLs) sources (through spectral beam combining or coherent beam combining) or other resonant gain media structures - where the result is a single mode - where emissions has already been demonstrated from fiber lasers, but can potentially be replaced by a single PCSEL integrated optical device - opens up the possibility of high energy laser (HEL) single stage output. The Navy desires higher power, higher efficiency laser and optics to increase engagement ranges, even in adverse marine atmospheric conditions.

The Navy seeks an approach with a scalable demonstration device in the evaluation of new combinable PCSEL devices that support Electro-magnetic (EM) Spectrum warfare dominance with an objective of gaining military advantages through increased laser power and efficiency - achieving freedom of action across missions in support of maritime, surface warfare.

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by 32 U.S.C. § 2004.20 et seq., National Industrial Security Program Executive Agent and Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence and Security Agency (DCSA) formerly Defense Security Service (DSS). The selected contractor and/or subcontractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances. This will allow contractor personnel to perform on advanced phases of this project as set forth by DCSA and ONR in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material during the advanced phases of this contract IAW the National Industrial Security Program Operating Manual (NISPOM), which can be found at Title 32, Part 2004.20 of the Code of Federal Regulations.

PHASE I: Develop, demonstrate, and deliver a small scale, efficient, coupled multi-aperture prototype PCSELs based high energy laser operating at 1.050-1.070 microns, suitable for testing and evaluation in a laboratory with output power measured in watts with a vertical and horizontal beam quality as close to the diffraction limit (M-squared=1.0, in horizontal and vertical dimensions) as possible. The device should include any required power and cooling to support a laser time of no less than 30 seconds. Provide multiple configurations and cross sections for initial laboratory testing.

Demonstrate the scalability in volume and combinability of individual PCSELs to increase power to achieve higher output power with higher beam quality based on the use of techniques such as nano-meter scale meta-surfacing modifications to die integrated electronic dies – showing improvements compared to standard manufacturing techniques.

Deliver one prototype to the Naval Research Laboratory to evaluate the performance of the system in terms of power specifications, wavelength, beam quality, and EO efficiency for a prototype laser system that can meet performance goals.

PHASE II: Develop, demonstrate, and deliver a batch scaled up (longer) prototypical high energy lasers, suitable for inclusion into a laser weapon system for testing and evaluation when mounted into an optical beam director with power combiner that is determined within the scope of Phase I. Document the design and demonstrate high power operation, including containment and ruggedization of the optical devices required on a shake table that emulates the motion and vibrational spectrum of Naval platform. Demonstrate higher efficiency and thermal stability of power gain amplifier fiber when individual components are integrated to achieve higher resulting beam quality and efficiency and compared to more traditional combined fiber laser gain media. Deliver the resulting prototype devices to the Naval Research Laboratory for evaluation of the performance of the subsystem components in terms of power specifications, wavelength, beam quality and EO efficiency – toward an anticipated HEL prototype system that would be used in field testing, reaching expected Navy performance goals. Prepare a Phase III commercialization/transition plan.

Work in Phase II may become classified. Please see note in Description section.

PHASE III DUAL USE APPLICATIONS: Support the Navy with technology transition for Department of War use. Show the scalability of source power from micro or milliwatt levels to multi-kilowatt class operation and beyond in the near infrared regime.

Ultimately, laser source subsystems will be deployed on surface ships, ground vehicles, or air vehicles – with potentials for other Navy or U.S. Marine Corps platforms to advance the future electromagnetic spectrum operational warfighting capabilities. Both the power specifications and wavelength of operation and electrical to optical (EO) efficiency will be tested at either the Naval Research Laboratory test facilities or Naval Surface Warfare Center, Dahlgren Division.

There is a potential for dual use of this system for manufacturing such as cutting/welding, optical communication and use in space or airborne platform for sensing. The most important characteristic of this wavelength is it is less affected by atmospheric absorption than visible wavelengths.

REFERENCES:

1. Noda, S. et al. "Photonic-crystal surface-emitting lasers." Nat Rev Electr Eng, Vol. 1, 2024. pp. 802-814. https://www.nature.com/articles/s44287-024-00113-x
2. Stevenson, R. "Promoting the PCSEL." Compound Semiconductor, Vol. 30, No. 9, 2024, pp. 30-34. https://compoundsemiconductor.net/article/120731/Promoting_the_PCSEL
3. King, Ben C. et al. "Coherent Power Scaling in Photonic Crystal Surface Emitting Laser Arrays." Optics & Applied Physics, 2019. https://doi.org/10.48550/arXiv.2011.04534
4. Kuznetso, Arseniy I. et al. "Roadmap for Optical Metasurfaces." CS Photonics 2024, 11, 3, pp. 816-865. https://doi.org/10.1021/acsphotonics.3c00457
5. National Industrial Security Program Executive Agent and Operating Manual (NISP), 32 U.S.C. § 2004.20 et seq. 1993". https://www.ecfr.gov/current/title-32/subtitle-B/chapter-XX/part-2004

KEYWORDS: High Energy Laser; Laser; Photonics; Crystals; Electro-Optics; Optical Efficiency; Electro Magnetic Spectrum; photonic-crystal surface-emitting laser; PCSEL

TPOC 1: Peter Morrison
peter.a.morrison.civ@us.navy.mil

TPOC 2: Christopher Wilson
christopher.r.wilson115.civ@us.navy.mil