Iodine-stabilized laser at telecom wavelength using dual-pitch periodically poled lithium niobate waveguide.

We demonstrate the third harmonic generation of a 1542-nm laser using a dual-pitch periodically poled lithium niobate waveguide with a conversion efficiency of 66%/W. The generated 514-nm light is used for saturation spectroscopy of molecular iodine and laser frequency stabilization. The achieved laser frequency stability is 1.

Evaluation of laser frequency offset locking using an electrical delay line.

Frequency offset locking between two Nd:YAG lasers is performed using frequency locking with an electrical delay line. The relative frequency instability of the offset locking is measured to be 3.5×10 for an averaging time of 1 s, which is approximately 77 times smaller than that of the free-running case.

Dual-frequency injection-locked continuous-wave near-infrared laser.

We report a dual-frequency injection-locked continuous-wave near-infrared laser. The entire system consists of a Ti:sapphire ring laser as a power oscillator, two independent diode lasers employed as seed lasers, and a master cavity providing a frequency reference. Stable dual-frequency injection-locked oscillation is achieved with a maximum output power of 2.

Retrieving angular distributions of high-order harmonic generation from a single molecule.

We present a novel method to retrieve angular distributions of high-order harmonic generation from a single molecule. This technique uses an iterative procedure based only on experimental results of time and angle-dependent harmonic signals, and no actual shape of molecular orbital is assumed. The molecular axis distribution in a target gas can simultaneously be deduced in this procedure.

Measurement of molecular rotational temperature in a supersonic gas jet with high-order harmonic generation.

We apply high-order harmonic generation to sensitive measurements of the molecular rotational temperature in a thin supersonic gas beam. The method uses nonresonant pump and probe femtosecond laser pulses to generate harmonic radiation from coherently rotating molecules. The rotational temperature of molecules can be derived accurately with high spatial and temporal resolutions from the Fourier spectrum of time-dependent signals.

Dynamic properties of angle-dependent high-order harmonic generation from coherently rotating molecules.

High-order harmonic generation from coherently rotating N2 and O2 molecules has been observed for different alignment angles in a pump and probe experiment using femtosecond laser pulses. The results obtained are in excellent agreement with those calculated using a recently developed theory, which represent the characteristic properties predicted for angle-dependent harmonic generation. It is shown that polarization geometry and alignment distribution play essential roles in potential applications to probe electronic structure and dynamics of molecular systems.