About

William North joined professor Choquette’s research group in 2020. He is a current US Army officer (LTC), received his Masters degree from Stanford University in 2013, and taught at the United States Military Academy from 2013-2016. He has worked on various projects involving semiconductor lasers and photonics ranging from the theory and modeling of lasers and photonic devices to the nano-/micro-fabrication and characterization of diode lasers.

Research

Coherently-Coupled Photonic Crystal VCSEL Arrays (2020-2023)

Coherently-coupled photonic crystal VCSEL arrays have been a focus area of the PDRG for many years. These devices have been shown to have numerous novel properties and behaviors. Perhaps most promisingly, when the lasers in an array are optically coupled their modulation bandwidth increases and noise decreases, making these devices a candidate for the next generation of optical communications laser transmitters. However, tuning multiple lasers into the coherently-coupled operating regime has been a challenge.

William has worked on developing automated spectral measurement and characterization techniques for VCSEL arrays. This techniques developed is detailed in William’s 2021 CLEO Poster presentation. Additionally, William has investigated the affect of having multiple modes in the cavity and the resulting effect on the far field.

Beam Quality of Photonic Crystal VCSEL (2015-2016)

William built a M2 measurement system and characterized the M2 values for various oxide confined VSCELs. This work is summarized in the 2016 Photonics West paper.

Publications

Journal Articles

• W. North, N. Jahan, P. Strzebonski, A. Khurana, S. E. Ralph, and K. D. Choquette, “Analysis and Characterization of Photon-Photon Resonance in Coupled Dual Element Photonic Crystal Vertical Cavity Surface Emitting Laser Arrays,” Journal of Lightwave Technology, submitted.

• W. North, N. Jahan, P. Strzebonski, and K. D. Choquette, “Modal characteristics of coupled vertical cavity surface emitting laser diode arrays,” Journal of Applied Physics, vol. 132, no. 17, p. 173102, Nov. 2022, doi: 10.1063/5.0119912.

• N. Jahan, W. North, and K. D. Choquette, “Supermode dynamics in coherent VCSEL arrays,” in Vertical-Cavity Surface-Emitting Lasers XXVI, Mar. 2022, vol. 12020, pp. 59–64. doi: 10.1117/12.2615567.

• P. Strzebonski, W. North, and K. D. Choquette, “Fourier-method beam analysis for coherent vertical cavity surface emitting laser arrays,” J. Opt. Soc. Am. A, JOSAA, vol. 39, no. 4, pp. 563–570, Apr. 2022, doi: 10.1364/JOSAA.446584.

• P. J. Strzebonski, W. North, N. Jahan, and K. D. Choquette, “Analysis of Coherence and Coupling in Vertical Cavity Surface Emitting Laser Arrays,” IEEE Journal of Quantum Electronics, pp. 1–1, 2022, doi: 10.1109/JQE.2022.3149143.

• N. Jahan, W. North, P. Strzebonski, and K. D. Choquette, “Supermode Switching in Coherently-Coupled Vertical Cavity Surface Emitting Laser Diode Arrays,” IEEE Journal of Selected Topics in Quantum Electronics, vol. 28, no. 1, pp. 1–5, Jan. 2022, doi: 10.1109/JSTQE.2021.3117236.

• P. Strzebonski, H. Dave, K. Lakomy, N. Jahan, W. North, and K. Choquette, “Computational methods for VCSEL array characterization and control,” in Vertical-Cavity Surface-Emitting Lasers XXV, Online Only, United States, Mar. 2021, p. 18. doi: 10.1117/12.2585066.

  • Abstract (PDF)
  • Manuscript (PDF)
  • Presentation (PDF)

• W. North, “Attack-Based Network Defense,” Cyber Def. Rev., vol. 6, no. 3, pp. 129–136, 2021.

• J. T. Blane, W. North, P. R. Zeidler, J. B. Dencker, D. B. Chacko, B. Souhan, K. A. Ingold, and J. J. Raftery, “Beam quality study for single-mode oxide-confined and photonic crystal VCSELs”, Proc. SPIE 9766, Vertical-Cavity Surface-Emitting Lasers XX, 97660I (4 March 2016).

• W. North, D. Chacko, P. Zeidler, J. Blane, K. Ingold, B. Souhan, and J. J. Raftery, “Measuring M2 values for On-Wafer Vertical Cavity Surface Emitting Lasers,” in Frontiers in Optics 2015, OSA Technical Digest (online) (Optical Society of America, 2015), paper JW2A.30.

Conference Proceedings

• W. North and K. D. Choquette, “Supermode Evolution in Dual Element Coupled VCSEL Arrays”, CLEO, San Jose, CA (May 2023).

• K. D. Choquette, N. Jahan, W. North, S. Ralph, J. Tatum, “Supermode Dynamics in Coherent VCSEL Arrays,” SPIE Photonics West, San Francisco, CA (Jan. 2022).

• N. Jahan, W. North, and K. D. Choquette, “Quantification of Coherent-Coupling in Photonic Crystal Vertical Cavity Laser Arrays,” International Semiconductor Laser Conference, Potsdam, Germany & virtual (Oct. 2021).

• K. D. Choquette, S. E. Ralph, A. Melgar, N. Jahan, W. North, and J. A. Tatum, “Supermode Dynamics for VCSEL Modulation,” IEEE Photonics Conference, virtual (Oct. 2021).

• W. North, N. Jahan, P. Strzebonski, and K. D. Choquette, “Spectral Mode Analysis of Non-Hermitian Phased Microcavity Laser Array," Conference on Lasers and Electro-Optics, virtual (May 2021).

• R. Kumar, K. A. Lakomy, W. North, P. Strzebonski, and K. D. Choquette, “Integrated Dielectric Micro-Optical Elements on VCSELs using Greyscale Lithograhy," Conference on Lasers and Electro-Optics, virtual (May 2021).

• P. K. Strzebonski, W. North, N. Jahan, and K. D. Choquette, “Machine Learning Analysis of 2x1 VCSEL Array Coherence and Imaginary Coupling Coefficient," Conference on Lasers and Electro-Optics, virtual (May 2021).

  • Abstract (PDF)
  • Slides (PDF)
  • Poster (PDF)

• N. Jahan, W. North, P. K. Strzebonski, K. A. Lakomy, and K. D. Choquette, “Extraction of Coupling Coefficient for Coherent 2x1 VCSEL Array, Conference on Lasers and Electro-Optics, virtual (May 2021).

• J. J. Raftery, W. North, J. Blane, D. Chacko, P. Zeidler, B. Souhan, K. Ingold. “Advancing the State-of-the-Art of Semiconductor Lasers for Optical Interconnects,” presented at the NSA Symposium 2016, Ft. Meade, MD, March 2016.

• D. Chacko, J. Wilkes, M. Rapp, J. Blane, W. North, B. Souhan, and J. Raftery. “Characterizing VCSEL Sources: Measuring and Comparing Beam Quality,” presented at the 2015 Mid-Atlantic ASEE Conference, Villanova, PA, April 2015.