Single-photon avalanche diode (SPAD) imagers typically have a relatively low fill factor, i.e. a low proportion of the pixel's surface is light sensitive, due to in-pixel circuitry. We present a microlens array fabricated on a 128×128 single-photon avalanche diode (SPAD) imager to enhance its sensitivity. The benefits and limitations of these light concentrators are studied for low light imagin...

We report on the development of a doubly weighted Gerchberg-Saxton algorithm (DWGS) to enable generation of uniform beamlet arrays with a spatial light modulator (SLM) for use in multiphoton multifocal imaging applications. The algorithm incorporates the WGS algorithm as well as feedback of fluorescence signals from the sample measured with a single-photon avalanche diode (SPAD) detector array....

A monolithic circuit has been designed for active-quenching and active-reset of single-photon avalanche diodes (SPADs), which operate above the breakdown voltage BD for detecting single photons. To the best of our knowledge, this is the first fully integrated circuit of this kind ever reported. It can operate with any available SPAD device, since it generates pulses high enough to quench detect...

New equations for paralyzable, non paralyzable and hybrid DT models, valid for any time dependent sources are presented. We show how such new equations include the equations already used for constant rate sources, and how it's is possible to correct DT losses in the case of time dependent sources. Montecarlo simulations were performed to compare the equations behavior with the three DT models. ...

A high-speed and hardware-only algorithm using a center of mass method has been proposed for single-detector fluorescence lifetime sensing applications. This algorithm is now implemented on a field programmable gate array to provide fast lifetime estimates from a 32 × 32 low dark count 0.13 μm complementary metal-oxide-semiconductor single-photon avalanche diode (SPAD) plus time-to-digital conv...

We demonstrate a new single-photon avalanche diode (SPAD) device, which utilizes the silicon-dioxide shallow-trench isolation (STI) structure common to all deep-submicron CMOS technologies, both for junction planarization and as an area-efficient guard-ring. This makes it possible to achieve an order-of-magnitude improvement in fill factor and a significant reduction in pixel area compared with...

Time-of-flight (TOF) measurements using pulsed light beams for 3D imaging or profiling require either a costly mechanical device to scan the scene [1] or a short and highly energetic optical pulse to flood the scene with photons [2]. An alternative to these methods is the use of detector arrays based on single photon avalanche diodes (SPADs) operating in Geiger mode [3]. These devices accuratel...

In the next generation Internet, the network will evolve from a plain communication medium into one that provides endless services to the users. These services will be composed of multiple cooperative distributed application elements. We name these services overlay applications. The cooperative application elements within an overlay application will build a dynamic communication mesh, namely an...

Abstract– The design and fabrication of integrated microlenses for CMOS single-photon avalanche diodes (SPADs) is presented in this paper. The micro-lens exploits the avalanche propagation phenomenon occurring in abrupt single-sided junctions and is achieved by carful design of the SPAD in a standard CMOS process. In contrast to an optical micro-lens, the proposed technique is more robust to m...

We developed a fully digital implementation of the Silicon Photomultiplier. The sensor is based on a single photon avalanche photodiode (SPAD) integrated in a standard CMOS process. Photons are detected directly by sensing the voltage at the SPAD anode using a dedicated cell electronics block next to each diode. This block also contains active quenching and recharge circuits as well as a one bi...