ABSTRACT
A new method of steering THz pulses radiated from a thin emitter excited by tilted optical pulse-fronts has been developed theoretically and validated in a proof-of-concept experiment. This steering technique is potentially efficient and rapid, and it should benefit from a THz-pulse energy that can scale with optical-beam size and magnitude. Conversely, the method employed for measuring the steered THz pulses is also capable of characterizing the pulse-front tilt of an optical beam.
ABSTRACT
We demonstrate the reconstruction of one- and two-dimensional objects by numerically backpropagating measured scattered terahertz transients. The spatial resolution determined by the Sparrow criterion is found to correspond to approximately 30% of the peak wavelength and 85% of the mean wavelength of the power spectrum of the single-cycle waveform.
ABSTRACT
The phase and amplitude noise spectra of a self-mode-locked Ti:sapphire laser are measured and compared with the noise characteristics of a colliding-pulse mode-locked (CPM) dye laser. The timing jitter of the Ti:sapphire laser is found to be approximately half that of the CPM laser for jitter rates above 50 Hz. The amplitude noise of both lasers is comparable for frequencies of as much as several hundred kilohertz. However, between 0.5 and 5 MHz the noise spectrum of the Ti:sapphire laser is 126-134 dB below the carrier, while the CPM laser noise is limited by the pump laser at 115-131 dB below the carrier.
