Current image sensors offer a raw output that incorporates a bayer color filter pattern, and additional processing is required to obtain a full color image. This paper presents a bilinear interpolation algorithm to demosaick images with bayer color pattern; the algorithm is implemented in a single field programmable gate array (FPGA) device using a pipelined architecture. A comparison between images obtained with the FGPA-based interpolation and a software-based interpolation using Matlab demosaicking function is presented. The proposed FPGA demosaick algorithm achieves reasonable image quality, and it is an economic alternative for smart camera devices.

In this paper, we present an experimental method demonstrating an improvement in the resolution of optically sampled time-interleaved analog-to-digital converters (ADCs) by applying a data averaging technique. We implemented two experiments for oversampling four times the bandwidth of an analog input signal using a multichannel time-interleaved arrangement. The sampling rate for each experiment was 2.08 gigasamples per second. In the first experiment, the optically sampled signal of each channel is digitized by a single ADC, whereas in the second, the signal is simultaneously digitized by four ADCs, and thereafter, the four digitized samples are averaged. A 20-dBm white-noise signal was superimposed on the input analog signal to test the implemented ADC systems. An improvement in the signal-to-noise-and-distortion ratio from 55.58 to 61.44 dB was achieved with averaging. Likewise, an improvement in the effective number of bits from 8.94 to 9.91 was achieved with averaging.

Predictions for the photon absorption coefficient (α) and photoluminescence (PL) of quasitype II CdS/ZnS core/shell nanocrystals [quantum dots (QDs)] have been obtained using a straightforward developed procedure. The developed procedure begins by solving the three-dimensional (3-D) Schrodinger equation written in spherical coordinates. Then, α is obtained by solving an equation based on the strict k-selection approach, and PL is derived by solving the Kubo–Martin–Schwinger relationship. This formulation allows the prediction of fundamental QD energy properties as a function of the QD radius. The predicted properties include quantized energy levels, effective bandgap, effective photon absorption wavelength, and effective photon emission wavelength. In addition, CdS/ZnS QDs were synthetized and stabilized based on previously reported procedures. Experimental measurements of α and PL were found to be very well matched to the calculated results. Hence, the developed procedures can be of great interest for designers who correlate theoretical results with experimental measurements to predict next generation QD performance for nanophotonics applications.

The nonlinear response of p-i-n photodiodes (PIN-PDs) has become a concern for circuit designers implementing PIN-PD-based switches because this response can significantly compromise systems performance. A major challenge with this implementation is the selection of an appropriate linear operation range from the I-V curve of the PIN-PD to reduce nonlinear effects. In this letter, a set of equations is derived to determine an operation point at the fourth-quadrant of the I-V curve. The determined operation point establishes a range of linear excursion for the peak-to-peak voltage input signal. The theoretical results obtained from linear approximation and numerical simulations were compared with practical measurements obtained from a switching circuit implemented with a commercial PIN-PD.

CdS, CdTe, Hg_0.1Cd_0.9Te, CdTe, and Ag films were progressively electrodeposited on ITO-coated soda–lime glass to manufacture a short- and mid-wavelength infrared photodetector. A distinctive feature of the applied electrodeposition method is the use of a non-aqueous solution containing ethylene glycol (EG) as the electrolyte in a traditional three-electrode configuration for every film deposition. Using EG as a supplementary electrolyte and using the same deposition conditions with a potential below 0.75 V for all film coatings reduces their environmental incompatibility and offers a low-cost and low-energy route for fabricating the reported photodetector. The produced photodetector has a sensitivity of up to ≈957 nm with a detectivity (D*) of 2.86 × 10¹² cm Hz^1/2 W⁻¹ and a dark current density (J_dark) of 10⁻⁶ mA cm⁻². Furthermore, the manufactured photodiode exhibits self-powered performance because V_oc and J_sc are self-generated, unlike previously reported photodiodes. The presented all-layer electrodeposition assembly approach can easily be adapted to fabricate sensing devices for different applications.