Hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS) offers accurate thermometry at kHz rates for combustion diagnostics. In high-temperature flames, selection of probe-pulse characteristics is key to simultaneously optimizing signal-to-nonresonant-background ratio, signal strength, and spectral resolution. We demonstrate a simple method for enhancing signal-to-nonre...

polyphase is a common class of pulse compression waveforms in the radar systems. oppermann code is one of the used codes with polyphone pattern. after compression, this code has little tolerant against doppler shift in addition to its high side lobe level. this indicates that the use of oppermann code is an unsuitable scheme to radars applications. this paper shows that the use of amplitude wei...

properties. The memory holding characteristics of this modulator were investigated experimentally in detail. Then it became clear as a result that there are two modes in the mechanism of the write-in and the readout. The linearity of the readout pulse width characteristics becomes better if the amount of the fl ux written in is controlled by the constant voltage by means of negative feedback. T...

In this paper we present a dual-mode thirdorder continuous time Σ∆ modulator that combines noise-shaping and pulse-width-modulation (PWM). In our 0.18 μm CMOS prototype chip the clock frequency equals 1GHz, but the PWM carrier is only around 125 MHz. By adjusting the loop filter, the ADC bandwidth can be set to 5 or 10 MHz. In the 5 MHz mode the peak SNDR equals 64dB and the dynamic range 71dB....

Ultrafast pulses on the femtosecond time scale allow fundamental processes, such as atomic transitions, to be measured. To investigate the formation of optical pulses, an argon ion laser was used to pump a titanium-doped sapphire laser. The mode-locked output of this laser was measured with a spectrometer and an autocorrelator to find a frequency pulse width of σω = 86 ± 3 rad/ps and a temporal...