In this paper, we present a high accuracy laser range finder and velocimeter using ultra-fast time-to-digital converter (TDC). The system operation is based on the measuring the round-trip time of a narrow laser pulse. A low-dark current high-speed PIN photodiode is used to detect the triggered laser beam and to produce start signal. The pulsed laser diode generates 45W optical power at 30ns du...

An improved one-dimensional (1-D) analysis of CMOS photodiode has been derived in which the effect of the substrate, which forms a high–low junction with the epitaxial layer, has been included. The analytical solution was verified with numerical simulations based on parameters extracted from a standard 0.35 m CMOS process. Two empirical parameters are suggested to offset the unavoidable inaccur...

Multiple-beam optical traps facilitate advanced trapping geometries and exciting discoveries. However, the increased manipulation capabilities come at the price of more challenging position and force detection. Due to unrivaled bandwidth and resolution, photodiode based detection is preferred over camera based detection in most single/dual-beam optical traps assays. However, it has not been tri...

Four different pixel architectures to be used in CMOS based indirect time-of-flight (ToF) rangers were designed, fabricated and characterised. The measured results are presented here for their direct comparison. Sharing a very similar, yet case optimised readout circuitry in each case, three fabricated CMOS rangers were based respectively on a pinned photodiode (PPD), a photogate, and a newly d...

In a direct detection receiver, incoming optical light wave electric field Er at receiver input is directly converted to an electrical current using a PIN-photodiode. When Er is weak, then an avalanche photodiode is used. So, the question is what do these diodes do and why/when is one preferred over the other. (Please refer to block diagram Fig 9.1(a)) To provide a brief introduction, photodiod...

This paper presents a monolithic optical detector, consisting of an integrated photodiode and a pre-amplifier in a standard 0.18μm CMOS technology. 3Gb/s data-rate was achieved at λ=850nm with an average optical power of 25 μW and BER10. This data-rate is over half an order of magnitude higher than that of current state-of-the-art optical detectors in standard CMOS. High speed operation is achi...

We study the effect of photodiode angular response on the measurement of surface plasmon resonance (SPR) in metallic thin films using the Kretschmann-Raether configuration. The photodiode signal depends not only on the light intensity but also on the incidence angle. This implies that the photodiode sensitivity changes along the SPR curve. Consequently, the measured SPR spectrum is distorted, t...

CMOS image sensors have become very popular in low cost imaging devices. In order to realize images of high quality, the image sensors need to have a high resolution, be able to achieve a high Signal-to-Noise ratio (SNR) and have a wide dynamic range. To increase the spatial resolution of the image sensors, the pixel size has been scaling down allowing integration of more pixels in a given die ...

To date, the photodiode still the first choice component is used in optical communication, especially for visible light communication (VLC) system. It has advantages of speed, energy consumption, and sensitivity, compared to other devices (e.g. image sensor). There are many practical implementations of high-speed VLC which uses photodiode. Commercially available photodiode typically have specif...