This paper describes a solution to suppress the base line problem in DLTS spectroscopy using a lock-in amplifier. The method has been used to characterize deep levels in a GaAs Schottky diode. Comparison with the classical method based on the use of a capacitance meter in the differential mode is established. The electric field dependence of the DLTS signal in a weakly doped semiconductor is al...

The optical gain-depletion-induced mode-locking dynamics of a semiconductor optical-amplifier-based fiber ring laser (SOAFL) backward injected by a purely sinusoidally modulated or digitally encoded distributedfeedback laser diode are theoretically and experimentally demonstrated. The effect of gain depletion and waveform on the mode-locked pulse width, pulse shape, and power of the SOAFL are i...

The limit of low current measurement using logarithmic current to voltage converter is improved by 6–7 orders of magnitude with the use of diodes of large band gap as compared with silicon diodes. Low cost commercially available light emitting diodes (LEDs) have been used for this purpose. A theoretical study and experimental measurement of device constant and reverse saturation currents of the...

Precision rectifiers are important building blocks for analog signal processing. The traditional approach based on diodes and operational amplifiers (OpAmps) exhibits undesirable effects caused by limited OpAmp slew rate and diode commutations. In the paper, a full-wave rectifier based on one CDTA and two Schottky diodes is presented. The PSpice simulation results are included.

Steady State Visually Evoked Potentials have been known for several decades and they appear in the primary visual cortex of brain as a result of light stimulation of the sense of sight. In this article a simple method for electroencephalographic data acquisition is presented. The system is based on the DSM-51 unit connected to goggles with blinking diodes and Mindset-1000 EEG amplifier with 16 ...

Continuous-wave mid-infrared radiation near 3.5 mm is generated by difference-frequency mixing of the output of a compact 1.1 1.5-mm dual-wavelength fiber amplif ier in periodically poled LiNbO3. The diode sidepumped amplif ier is constructed with double-cladding Yb-doped fiber followed by single-mode Er/Yb codoped fiber. Output powers of as much as 11 mW at 3.4 mm are obtained, and spectroscop...

Erbium-doped Y203 integrated optical amplifiers are designed for low-threshold operation and 3dB amplification. The most important design parameter for minimal threshold, the erbium concentration, is found to have an optimum value of 0.35 at% for a given waveguide structure with 1.0dBcm -1 background loss. The corresponding threshold power is 7 mW. The pump power to obtain 3dB gain is found to ...