Quantum Dot Sensor Company SWIR Vision Raises $5M in A-Round

Optics.org, EINPressWire: SWIR Vision Systems, a Durham, North Carolina, company developing colloidal quantum dots (CQDs) image sensor has raised $5M in a round A of funding. SWIR Vision Systems has been founded in 2018 as a spin-off from the Research Triangle Institute. The company's “Acuros” family of thermoelectrically cooled CMOS-based CQD sensors reaches 2.1MP resolution.

“While InGaAs SWIR cameras are generally constrained to 640×512 or 1280×1024 pixel formats, our pioneering CQD sensor technology enables 2.1 megapixel, full-HD resolution, the first commercially available SWIR product of its kind.”

The new eSWIR version of the product family operates across an extended wavelength range, between 350 nm and 2000 nm, with a pixel pitch of 15 µm. 

The company's Vimeo video compares regular RGB imaging with SWIR in foggy environment.

China Domestic Market Dynamics

Sohu: Sunrise Big Data publishes its analysis of unit volume CIS market in Q1 2021. Galaxycore quickly captures a market share from Sony, Samsung, and Omnivision, as compared with Q4 2020:

"According to Sunrise Big Data statistics, global smartphone CMOS image sensor shipments in Q1 2021 will be 1.413 billion, of which Galaxycore will ship about 447 million, accounting for 31.6% , ranking first.

According to the observation, Galaxycore has also become a sensor head supplier in the security, automotive and other sub-sectors. In the first half of 2021 , Galaxycore CIS non-mobile phone business revenue has exceeded 100 million US dollars , exceeding the full year of 2020."

ToF Basics by Terabee

Terabee publishes a few webinars on ToF technology basics and applications:

TI Proprietary V3Link Competes with MIPI A-PHY

TI presentation "V3Link Industrial SerDes" unveils the company's approach to compete with MIPI A-PHY and Auto-Serdes standards:

Smartsens Improves its AI Sensor Series

CoreIntelligence (Google translation): SmartSens keeps a high pace of incremental improvements and launches three new 4MP image sensors in AI series (AI stands for Advanced Imaging) for security applications-SC400AI, SC401AI, and SC433:

"The performance has been significantly improved compared with the previous generation products. It is equipped with Smartsens' innovative SFCPixel patented technology, which can achieve excellent night vision full-color imaging effects.

In addition, thanks to the PixGain dual-pixel conversion gain technology, SC401AI improves the image quality while further expanding the applicability of terminal products. As a product of the same specification as SC401AI, SC400AI has a frame rate of up to 60fps and can support 30fps dynamic line overlap HDR (Staggered HDR) image output, which provides customers with more choices while imaging performance is upgraded.

Compared with the previous generation products, the full well electrons of SC400AI and SC401AI have increased by 48.6%, the dynamic range has increased by 3dB, and the QE (quantum efficiency) in the 520nm band has increased by 42%."

Applied Materials' DTI Optimizations for CIS

Applied Materials master class presentation for investors shows the company's efforts on image sensor DTI process refinements:

AAA Tests: Camera-Based ADAS Fails in Rain

AAA: New research from AAA finds that moderate to heavy rain affects a vehicle safety system’s ability to “see”, which may result in performance issues. During closed course testing, AAA simulated rainfall and found that test vehicles equipped with automatic emergency braking traveling at 35 mph collided with a stopped vehicle one third (33%) of the time. Lane keeping assistance didn’t fare any better with test vehicles departing their lane 69% of the time. Vehicle safety systems, also known as advanced driver assistance systems or ADAS, are typically evaluated in ideal operating conditions. However, AAA believes testing standards must incorporate real-world conditions that drivers normally encounter.

“Vehicle safety systems rely on sensors and cameras to see road markings, other cars, pedestrians and roadway obstacles. So naturally, they are more vulnerable to environmental factors like rain,” said Greg Brannon, AAA’s director of automotive engineering and industry relations. “The reality is people aren’t always driving around in perfect, sunny weather so we must expand testing and take into consideration things people actually contend with in their day-to-day driving.”

An AAA video shows that even a moderate rain interferes with the camera-based emergency braking:

IEDM 2021: Canon Presents 3.2MP SPAD Sensor for Low-Light Imaging

IEDM publishes few pictures from Canon's IEDM paper #20.2, “3.2 Megapixel 3D-Stacked Charge Focusing SPAD for Low-Light Imaging and Depth Sensing,” K. Morimoto/J. Iwata et al.

3D Backside-Illuminated SPAD Imager Sensors: Unlike the CMOS image sensors found in smartphones, which measure the amount of light reaching a sensor’s pixels in a given timeframe, single photon avalanche diode (SPAD) image sensors detect each photon that reaches the pixel. Each photon is converted into an electric charge, and the electrons that result are eventually multiplied in avalanche fashion until they form an output signal. SPAD image sensors hold great promise for high-performance, low-light imaging applications, for depth sensing, and for fully digital system architectures.

However, until now their performance has been limited by tradeoffs in pixel detection efficiency vs. pixel size, and by poor signal-to-noise ratios. Recently a charge-focusing approach was proposed to overcome these issues, but until now it remained to be implemented. In a late-news paper, Canon researchers will discuss how they did so, with the industry’s first 3D-stacked backside-illuminated (BSI) charge-focusing SPADs. The devices featured the largest array size ever reported for a SPAD image sensor (3.2 megapixels) and demonstrated a photon detection efficiency of 24.4%, and timing jitter below 100ps at 940 nm.

From the images below:

(a) is a full-resolution color intensity image captured by the 3.2megapixel SPAD image sensor at a high light level.

(b) is a monochrome intensity image captured by the device under a scene illumination of 2mlux (without post-processing)

(c) is a monochrome intensity image captured by the device under a scene illumination of 0.3mlux (without post-processing)

a full-resolution color intensity image captured
by the 3.2megapixel SPAD image sensor
at a high light level.

a monochrome intensity image captured
 by the device under a scene illumination
 of 2mlux (without post-processing)

a monochrome intensity image captured
by the device under a scene illumination
 of 0.3mlux (without post-processing)

2021 Walter Kosonocky Award

 ST reports at its Facebook page:

"ST’s Francois Roy succeeds in solid-state image sensors

The International Image Sensor Society recently gave François Roy the Walter Kosonocky Award for his paper entitled Fully Depleted Trench-Pinned Photo Gate for CMOS Image Sensor Applications. The Photo Gate pixel concept improves image quality and the manufacturing process.

‘’It is a great honor for ST, the ST Imaging teams, my PhD students and myself to receive this prestigious award and I thank them all,’’ said François.

At ST we are proud of our inventors. We nurture strong competences and encourage our distinguished senior experts to coach young engineers."

HDR in iToF Imaging

Lucid Vision Labs shows two nice demos of HDR importance in ToF imaging. The demos are based on its Helios2+ camera with Sony IMX556 iToF sensors:

2014 Imaging Papers

IEEE Sensors keeps publishing 2014 papers video presentations:

Review of Methods for Resolving Multi-Path Interference in Time-of-Flight Range Cameras

Author: Refael Whyte, Lee Streeter, Michael Cree, Adrian Dorrington

Affiliation: University of Waikato, New Zealand

Abstract: Time-of-Flight (ToF) range cameras measure distance for each pixel by illuminating the entire scene with amplitude modulated light and measuring the change in phase between the emitted light and reflected light. One of the most significant causes of distance accuracy errors is multi-path interference, where multiple propagation paths exist from the light source to the same pixel. These multiple propagation paths can be caused by inter-reflections, subsurface scattering, edge effects and volumetric scattering.  Several techniques have been proposed to mitigate multi-path interference. In this paper a review of current techniques for resolving measurement errors due to multi-path interference is presented, as currently there is no quantitative comparison between techniques and evaluation of technique parameters. The results will help with the selection of a multi-path interference restoration method for specific time-of-flight camera applications.

Optimization of Perimeter Gated SPADs in a Standard CMOS Process

Author: Mohammad Habib, Farhan Quaiyum, Syed Islam, Nicole McFarlane

Affiliation: University of Tennessee, Knoxville, United States

Abstract: Perimeter-gated single photon avalanche diodes (PGSPAD) in standard CMOS processes have increased breakdown voltages and improved dark count rates. These devices use a polysilicon gate to reduce the premature breakdown of the device. When coupled with a scintillation material, these devices could be instrumental in radiation detection. This work characterizes the variation in PGSPAD noise (dark count rate) and breakdown voltage as a function of applied gate voltages for varying device shape, size, and junction type.

A Low-Noise High-Sensitivity CMOS Image Sensor for Scientific and Industrial Applications

Author: Min-Woong Seo, Taishi Takasawa, Keita Yasutomi, Keiichiro Kagawa, Shoji Kawahito

Affiliation: Shizuoka University, Japan

Abstract: A low-noise high-sensitivity CMOS image sensor for scientific use is developed and evaluated. The prototype sensor contains 1024(H) × 1024(V) pixels with high performance column-parallel ADCs. The measured maximum quantum efficiency (QE) is 69 % at 660 nm and long-wavelength sensitivity is also enhanced with a large sensing area and the optimized process. In addition, dark current is 0.96 pA/cm2 at 292 K, temporal random noise in a readout circuitry is 1.17 electrons RMS, and the conversion gain is 124 uV/e-. The implemented CMOS imager using 0.11-um CIS technology has a very high sensitivity of 87 V/lx*sec that is suitable for scientific and industrial applications such as medical imaging, bioimaging, surveillance cameras and so on.