We present a novel direct space-to-time pulse shaper, operating in the 1.5m optical communications band which enables generation of continuous optical pulse sequences at a rate of 100GHz. The apparatus includes several novel features, such as the use of a diffractive optical element for spatial patterning, fiber coupled input/output, and a telescopic configuration which collectively enable gene...

A single pulse modulation and pseudorandom coded pulse modulation are utilized for water vapor DIAL in this paper. The water vapor profiles conducted from these modulation techniques are compared to the real observation data in summer in Japan. As a result, the single pulse modulation is appropriate for near region measurement, while pseudorandom coded pulse modulation is appropriate for far re...

The article reports the excitation of a helical argon atmospheric pressure plasma jet using pulse-modulated 13.56 MHz radio frequency (RF) power source. This structure is observed in open ambient air, which far different from conventional conical shape. originates due to periodic variation discharge region caused by RF (2 kHz modulation frequency) and propagates downstream into air. geometrical...

A Space Vector based Pulse Width Modulation control technique for the three-phase PWM converter is proposed in this paper. The proposed control scheme is based on a synchronous reference frame model. High performance and efficiency is obtained with regards to the DC bus voltage and the power factor considerations of the PWM rectifier thus leading to low losses. MATLAB/SIMULINK are used as a pla...

When a target has a large velocity, the Doppler effect is not negligible. In that case, pulse compression by means of a linear frequency modulation suffers from significant signal loss in performance due to the mismatch between the reflected signal and the matched filter caused by the Doppler distortion. This problem can be avoided by using a hyperbolic frequency-modulated waveform, which has t...

the modulation response, relative intensity noise and frequency noise characteristics of qd lasers are investigated theoretically, in presence of an additional optical pumping. it is revealed that the modulation response of qd laser enhances under additional optical beam. by small signal analysis of the carriers' and photons' rates, it is proposed that by injecting excess carriers to ...

In this study, a novel Ultra Wideband (UWB) pulse generator design for singleand multi-user systems is presented. The proposed pulse generator is based on new simple and effective design to generate the UWB pulses through sine wave shaping. For single-user systems, three models for the proposed pulse generator working with Frequency Modulation (FM), Bi-Phase Modulation (BPM) and On-Off Keying (...

Turbulence of scroll waves is a sort of spatiotemporal chaos that exists in three-dimensional excitable media. Cardiac tissue and the Belousov-Zhabotinsky reaction are examples of such media. In cardiac tissue, chaotic behavior is believed to underlie fibrillation which, without intervention, precedes cardiac death. In this study we investigate suppression of the turbulence using stimulation of...

We report programmable shaping of femtosecond optical pulses by use of a multielement liquid-crystal modulator to manipulate the phases of spatially dispersed optical frequency components. Our approach provides for continuously variable control of the optical phase and permits the pulse shape to be reconfigured on a millisecond time scale. We use the apparatus to demonstrate femtosecond pulse-p...

Widefield frequency-domain fluorescence lifetime imaging microscopy (FD-FLIM) is a fast and accurate method to measure the fluorescence lifetime, especially in kinetic studies in biomedical researches. However, the small range of modulation frequencies available in commercial instruments makes this technique limited in its applications. Here we describe a practical implementation of multi-frequ...