A quantum random number generator QRNG based on gated single photon detection of an In– GaAs photodiode at gigahertz frequency is demonstrated. Owing to the extremely long coherence time of each photon, each photons’ wave function extends over many gating cycles of the photodiode. The collapse of the photon wave function on random gating cycles as well as photon random arrival time detection ev...

Solar cells and photodetectors are devices that convert an optical input into current. A solar cell is an example of a photovoltaic device, i.e, a device that generates voltage when exposed to light. The photovoltaic effect was discovered by Alexander-Edmond Becquerel in 1839, in a junction formed between an electrode (platinum) and an electrolyte (silver chloride). The first photovoltaic devic...

The detection of an optical signal using a photonic mixer device (PMD) as an alternative to the PIN photodiode for a high-speed infrared link is discussed. The PMD, at its linear range, is characterized as a correlator detector. The functionality of this PMD for a better Signal-to-Noise Ratio is described. With an improved mixing efficiency and photosensitive area, the PMD will replace the use ...

Balanced photodetection is a commonly used detection method in the lab when an experiment requires increased signal-to-noise. This detection method has many advantages to simply amplifying a signal with an amplifier following the photodiode. In some cases, it can also achieve better noise performance and sensitivity than an avalanche photodiode (APD). It is particularly powerful in its ability ...

A Large Area Avalanche Photodiode was studied, aiming to access its performance as light detector at low temperatures, down to 80 C. The excess noise factor, F ; was measured and found to be approximately independent of the temperature. A linear dependence of F on the APD gain with a slope of 0.0023970.00008 was observed for gains >100. The detection of low intensity light pulses, producing onl...

We investigate the axial position detection of a trapped microsphere in an optical trap by using a quadrant photodiode. By replacing the photodiode with a CCD camera, we obtain detailed information on the light scattered by the microsphere. The correlation of the interference pattern with the axial position displays complex behavior with regions of positive and negative interference. By analyzi...

: In this paper investigation has been done on two different photodiodes PIN and APD for use as a receiver in free space fiber optical link. Eye Diagrams have been used to evaluate value of Qfactor in each and every case. Gaussian pulse modulation format has been used in this analysis work. It is clear from the findings of this analysis that value of Q-factor is maximum when APD has been used a...

The calculation of symbol-error probabilities for uncoded pulse-position modulation using a Webb-modeled avalanche photodiode receiver in the presence of additive Gaussian thermal noise is discussed. Performance curves for 256-ary pulseposition modulation obtained through Monte Carlo simulation as well as a numerical upper bound are presented. The Webb-plus-Gaussian model for the distribution o...

A monolithically integrated optoelectronic receiver with a low-capacitance on-chip pin photodiode is presented. The receiver is fabricated in a 0.35 μm opto-CMOS process fed at 3.3 V and due to the highly effective integrated pin photodiode it operates at μW. A regenerative latch acting as a sense amplifier leads in addition to a low electrical power consumption. At 400 Mbit/s, sensitivities of...

We present a twin-beam light source based on quasi-phase-matched (QPM) continuous-wave (CW) optical parametric generator (OPG). The source emits collinearly the signal and the idler beams at a power level of 1 nW in wavelength ranges from 790 nm to 920 nm and from 1260 nm to 1620 nm, respectively, with a bandwidth of less than 2 nm. The quantum correlation in the OPG process can be used to dire...