About

Jonathan Klamkin is a Professor in the Department of Electrical and Computer Engineering at UC Santa Barbara. His research interests include integrated photonics, silicon photonics, optical communications, nanophotonics, microwave photonics, compound semiconductors, photonic integration techniques, and electronic-photonic integration. He is associated with the Integrated Photonics Laboratory (iPL) and is based in the Harold Frank Hall, Rm 4155. His contact information includes a phone number (+1 805-893-7163), email (klamkin@ece.ucsb.edu), and office location in the Engineering Science Building. Professor Klamkin's work focuses on advancing photonic technologies and their integration with electronic systems, contributing to the development of innovative solutions in optical communications and photonic integration.

Research topics

• Optoelectronics
• Nanotechnology
• Optics
• Computer Science
• Physics
• Materials science
• Telecommunications
• Electronic engineering
• Engineering
• Electrical engineering

Selected publications

• Broadband Low‐Loss Unidirectional Reflection On‐Chip with Asymmetric Dielectric Metasurface

  Laser & Photonics Review · 2025-06-05

  articleOpen access

  Abstract Metasurface has emerged as a powerful platform for controlling light at subwavelength thickness, enabling new functionalities for imaging, polarization manipulation, and angular momentum conversion within a flat surface. An integrated asymmetric metasurface simultaneously achieving broadband, low loss forward power transmission, and significant back reflection suppression in multi‐mode waveguides is explored. The tapering along the direction of light propagation leads to low loss and space‐efficient mode conversion. Enhanced by a double‐flipped structure, a thin (2.5 µm) metasurface can simultaneously achieve high conversion efficiency (>80%), and back‐reflection efficiency of 90% over a 200 nm wavelength range. Such single‐side reflectors can be one of the enabling components for gain‐integrated adaptive optics on a chip.

  PublisherOA PDFDOI

• High-Resolution Arrayed Waveguide Grating-Assisted Passive Optical Phased Array for 2D Beam Steering

  2025-01-03

  preprintOpen accessSenior author

  Optical phased arrays (OPAs) with arrayed waveguide gratings (AWGs) enable two-dimensional (2D) beam steering through wavelength tuning. Achieving a high vertical resolution for practical applications remains challenging due to the waveguide phase errors associated with the large AWG required. Here, we present a high-resolution 65-channel AWG-assisted OPA with 5 inputs. Ultra-low loss silicon nitride waveguide technology and transverse magnetic mode operation are employed for waveguide phase error mitigation. A vertical resolution of 0.3° using a single input is attained with a beam width of 0.55°× 0.07° and an alias-free horizontal field of view (FOV) of 30°. By utilizing all 5 inputs, the vertical resolution can be enhanced to 0.06°. Real-time 2D beam steering over a 25°× 5° FOV is demonstrated. To our knowledge, this work demonstrates the highest vertical resolution reported for an AWG-based OPA.

  PublisherOA PDFDOI

• Scalable and Monolithic Integration of Quantum Dot Lasers for Silicon Photonics

  2025-06-16 · 1 citations

  articleSenior author

  We report QD laser structures grown by MOCVD on silicon and monolithic integration on silicon photonic wafers by selective area heteroepitaxy scalable to 300 mm wafers. Growth by MOCVD minimizes the gap between the QD waveguide and a silicon nitride waveguide to facilitate coupling.

  PublisherDOI

• Corrections to “Quantum Dot DBR Lasers Monolithically Integrated on Silicon Photonics by In-Pocket Heteroepitaxy”

  Journal of Lightwave Technology · 2025-08-13

  article

  Presents corrections to the author listings in the paper, “Quantum Dot DBR Lasers Monolithically Integrated on Silicon Photonics by In-Pocket Heteroepitaxy,” (Koscica, R., et al., 2025).

  PublisherDOI

• Quantum Dot Photodetector and Laser Monolithically Integrated on Silicon Photonics

  ACS Photonics · 2025-08-25 · 4 citations

  articleOpen access

  III–V quantum dot (QD) photodetectors enable on-chip sensing in the telecommunications O-band with high responsivity and low dark current. We demonstrate for the first time III–V QD photodetectors monolithically integrated with silicon nitride waveguides and III–V QD lasers. III–V QD material is heteroepitaxially grown in pockets on silicon photonics coupons, where it is coprocessed into III–V ridge waveguides serving as both photodetectors and lasers. The photodetectors have a dark current of 250 pA and a responsivity of 0.344 A/W at a –2 V bias. Photodetectors integrated with lasers in a loop configuration correctly measure threshold current and in-waveguide optical power at the few-mW level. This work demonstrates multifunctional III–V devices on the silicon photonics platform, enabling a wider variety of monolithically integrated active components without the need for additional process steps.

  PublisherOA PDFDOI

• Heterogeneous Integration of InGaAs PIN and APD Photodetectors for High-Speed Interconnects

  2025-06-16

  articleSenior author

  This work presents heterogeneously integrated high-speed InGaAs PINs and APDs for shortwave wavelength division multiplexing optical interconnects. PIN photodiodes demonstrate low dark current and high external quantum efficiency, while APDs exhibit stable avalanche gain. The approach enables cost-effective, wafer-scale manufacturing with CMOS compatibility.

  PublisherDOI

• Tunable Quantum Dot Lasers Monolithically Integrated with Silicon Photonics Rings and DBR Gratings

  2025-01-01 · 2 citations

  article

  O-band quantum dot lasers are monolithically integrated on silicon photonics using MOCVD/MBE growth and a facet fill approach to reduce waveguide coupling loss below 6 dB. Lasers achieve ring resonator coupling and single-mode lasing.

  PublisherDOI

• Heterogeneous integration of compound semiconductors on silicon by direct heteroepitaxy (Conference Presentation)

  2025-06-05

  article1st authorCorresponding
  PublisherDOI

• Passive AWG-assisted Optical Phased Array for High-Resolution 2D Beam Scanning

  2025-04-14

  articleSenior author

  A high-resolution 65-channel arrayed-waveguide-grating-assisted passive optical phased array is reported based on an ultra-low loss silicon nitride platform. Two-dimensional (2D) beam steering over 25°× 5° field-of-view was demonstrated through 100 nm laser wavelength tuning with 0.06° vertical resolution and beam divergence of 0.55°× 0.07°.

  PublisherDOI

• High-resolution arrayed waveguide grating-assisted passive optical phased array for 2D beam steering

  Optics Express · 2025-02-03 · 3 citations

  articleOpen accessSenior author

  Integrated optical phased arrays (OPAs) based on arrayed waveguide gratings (AWGs) enable two-dimensional (2D) beam steering through wavelength tuning. Achieving a high vertical resolution for practical applications remains challenging due to the waveguide phase errors associated with the large AWG required. Here, we present a high-resolution 65-channel AWG-assisted OPA with 5 inputs. Ultra-low loss silicon nitride waveguide technology and transverse magnetic mode operation are employed for waveguide-phase-error mitigation. A vertical resolution of 0.32° using a single input is attained with a beam width of 0.55° × 0.07° and an alias-free horizontal field of view (FOV) of 30°. By utilizing all 5 inputs, the vertical resolution can be enhanced to 0.06°. Real-time 2D beam steering over a 25° × 5° FOV is demonstrated. To our best knowledge, this work demonstrates the highest vertical resolution reported for an AWG-based OPA.

  PublisherDOI

Frequent coauthors

• L.A. Coldren

  76 shared

• Bowen Song

  62 shared

• Leif A. Johansson

  Freedom Photonics (United States)

  46 shared

• Simone Tommaso Šuran Brunelli

  45 shared

• Sergio Pinna

  44 shared

• P Juodawlkis

  41 shared

• John E. Bowers

  40 shared

• Jason J. Plant

  38 shared