W&Wsens Devices Inc 

Thin Silicon Photosensors for the Next Generation


W&W breakthrough innovation : Lightwave trapping using microholes to enable high speed, low jitter and high sensitivity in thin Silicon photosensor arrays in the Red and NIR wavelength 

Lightwave Trapping
  • Microhole compatible with CMOS Trench Isolation Etch 

  • Enhance absorption in Thin Silicon 0.1 - 3 micron, 700 nm - 1000 nm wavelength 

  • EQE 85% @850 nm, 1 micron Si - WR 

  • Microholes on thin Ge on Si extend wavelength to 1700 nm

  • Low Jitter (<15ps), High data bandwidth >56Gb/s

Performance and Cost Reduction
  • Standard CMOS manufacturing process, unlike Black Silicon using pulsed laser process 

  • Monolithic Integration of photosensor arrays with CMOS ASICs or...

  • Stacked Technology of photosensor array with CMOS ASICs for BICIS

  • Low manufacturing cost due to Thin Silicon, 3 microns or less

  • High performance low parasitics 

  • Visible / NIR Imaging - single microhole for small pixels

  • 3D Imaging / Time of Flight Imaging 

  • AR / VR, Facial Recognition, LiDAR for ADAS, Security, Medical

  • 1 Tb/s aggregated data bandwidth - Optical Interconnect for Data Center 

  • 56, 6G high capacity optical link  


Core Application Sectors & Competitive Advantages 

W&Wsens Devices Technology Impact

W&Wsens Devices Microhole to Enhance Red and NIR Sensitivity for Stacked BICIS - Imaging and 3D Imaging 

Surface Illuminated Microstructure Hole Photodiodes
Si PIN Photodiode 
Ge on Si PIN Photodiode
Scanning Electron Microscope Images
Optical Field Distribution in Microstructure Hole PD using FDTD Simulation
Microstructure Hole PD / APD Results
Si PIN 850nm Impulse
Ge on Si PIN 1300nm Impulse


Si Absorption layer thickness < 2um

Responsivity Si APD

Multiplication M=1026 @ 850nm, 8.5uW


About W&W

Over a cup of cappuccino at a cafe in Palo Alto, W&Wsens Devices was conceived and in a few months grew to over 100 years of aggregated knowledge and experience in photonic devices, optical systems , innovation, IP,manufacturing, and start-ups. All team members come from Fortune 500 companies and / or start ups.

SP Bob Wang - CEO & Co-Founder 


Founder & Chairman of:

R2 (sold to Hologic), 

U-Systems (sold to GE),

EndoSee (sold to Cooper)

QView, and UroViu.

Shih-Yuan Wang - CTO & Co-Founder

BS, PhD UC Berkeley

HP Labs 200+ Patents

High speed photodetectors

Co-Inventor of Multimode VCSELS 

USPTO : 5,359,447 A

for Datacenter interconnect


Saif Islam - Professor UCD

UCD Collaboration



High speed photonic devices

Aly F. Elrefaie - Chief Scientist

BS Ain Shams University

MS & PhD NYU Engineering

Bellcore, HP Labs, Boeing,  

Optical communication systems

Toshishige Yamada - Principal Scentist

Physics for advanced materials and devices

BS, MS University of Tokyo

Ph.D Arizona State University 

NEC Labs, Japan

Semiconductor transport theory

Ekaterina (Katya) Ponizovskaya Devine

Principal Scientist, Theory

MS & PhD Moscow Institue of Physics and Technology 

HP Labs

Theory, numerical modeling

Lihan Wang -Vice President Strategy

& Business Development 

BA University of Michigan, Ann Arbor

MSc University of Leeds

Agora Labs, UBS 


Market Outlook


Intellectual Property

W&Wsens Devices Inc IP Portfolio
32 Issued Patents and Published Patent Applications, 100+ Provisional Patents Applications



Enhancement of light detection efficiency with microstructure holes in high speed photodetectors with reverse bias

Monolithic integration of microstructure holes photodetector with CMOS electronics for silicon & germanium on silicon structures.






















Publications & Media

Photon-Trapping Microstructures Enable High-Speed Efficiency Silicon Photodiodes ; Nature Photonics 2017
High Speed Surface Illuminated Si Photodiode Using Microstructured Holes for Absorption Enhancements at 900-1000nm Wavelength; ACS Photonics 2017
A New Paradigm in High-Speed and High-Efficiency Silicon Photodiodes for Communication Part I: Enhancing Photon-Material Interactions via Low-Dimensional Structures ; IEEE TED 2017
A New Paradigm in High-Speed and High-Efficiency Silicon Photodiodes for Communication Part II: Device and VLSI Integration Challenges for Low-Dimensional Structures ; IEEE TED 2017
High-Speed High-Efficiency Broadband Silicon Photodiodes for Short-Reach Optical Interconnects in Data Centers; OFC 2018
Surface Passivation of Silicon Photonic Devices with High Surface-to-Volume-Ratio Nanostructures ; Journal of the Optical Society of America B 2018
Surface-illuminated photon-trapping high-speed Ge-on-Si photodiodes with improved efficiency up to 1700nm ; Photonics Research OSA 2018
Enhanced Photon Detection Efficiency of Silicon Single Photon Avalanche Photodetectors Enabled by Photon Trapping Structure ; DOI:10.1109/PHOSST.2018.8456744 IEEE 2018
High-Speed High-Efficiency Photon-Trapping Broadband Silicon PIN Photodiodes for Short-Reach Optical Interconnects in Data Centers; IEEE Journal of Lightwave Technology 2019
Dramatically Enhanced Efficiency in Ultra-fast Silicon MSM Photodiodes with Photon-trapping Structures; IEEE Photonics Technology Letters 2019
Fast Silicon Photodiodes ; Nature Photonics
Silicon Nanostructures Bend Light to Make Faster Photodiodes ; IEEE Spectrum
Tiny Black Holes Enable a New Type of Photodetector for High Speed Data ; Phys.org
Nanoholes in Silicon Bolster Photodetector Speed, Efficiency ; Photonics.com
" Black Holes" in Silicon Enable High-Speed Photodetector ; Photonicsonline.com


W&Wsens Devices Inc.

4546 El Camino, Suite 215

Los Altos, Ca. 94022