Tai Hyun Yoon

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A sweep optical frequency synthesizer is demonstrated by using a frequency-stabilized optical frequency comb and injection-locked distributed-Bragg-reflector (DBR) laser diode. The injection-locked DBR laser acts as a single-frequency filter and, simultaneously, a high-gain amplifier of the optical frequency comb. The frequency instability of the heterodyne(More)
A widely tunable and high-resolution spectrometer based on a frequency-doubled Ti:sapphire laser was used to explore sub-Doppler transitions of iodine molecules in the wavelength range 523-498 nm. The wavelength dependence of the hyperfine transition linewidth of iodine was mapped out in this region, and the narrowest linewidth was ~4 kHz near 508 nm. The(More)
Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-ku, 305-70 1 Taejun, Korea, and Korea Atomic Energy Research Institute, P.O. Box 7, Taeduck Science Town, 353-606 Taejun, Korea The 7Fo 5Do excitation spectra of Eu(II1) complexed with soil fulvic acid (FA) were acquired over a range of solution pH(More)
A two-photon transition in cold Rb atoms will be probed with a phase-coherent wide bandwidth femtosecond laser comb. Frequency domain analysis yields a high-resolution picture where phase coherence among various transition pathways through different intermediate states produces interference effects on the resonantly enhanced transition probability. This(More)
We present a simple scheme for thermal frequency stabilization of a three-longitudinal-mode He-Ne laser at 633 nm with improved short-term (5 x 10(-11) at 1-s average time) and long-term (124-kHz standard deviation for 10 h) frequency stability. A stabilized output power of 3 mW was readily obtained from the central mode by polarization-mode selection. The(More)
We have demonstrated a device to produce an overlapping pair of orthogonally polarized laser beams with a 3 GHz frequency offset out of a single laser beam containing the two frequency components with the same linear polarization. Our design is based on a Michelson interferometer formed by a polarizing beam splitter and two quarter-waveplates. Such a device(More)
The absolute frequency of an iodine-stabilized He−Ne laser at 633 nm stabilized on the i (or a13) component of the 11-5 R(127) hyperfine transition of the I2 molecule is measured using a femtosecond optical comb generator and an iodine-stabilized Nd:YAG laser standard at 1064 nm. We link the measured absolute frequency to the current internationally adopted(More)
Photothermal treatment methods have been widely studied for their target specificity and potential for supplementing the limitations of conventional surgical treatments. In this study, we conducted in vivo photothermal treatments using macrophages containing nanoshells as live vectors. We injected macrophages at the peritumoral sites and observed that they(More)
We report on the experimental observations of a period-doubling route to chaos and a total mode-locking between two lowest-order lateral modes of a GaAs ridge wave-guide diode laser at 795 nm. A self-starting passively mode-locking was achieved in an extended-cavity diode laser (ECDL) operating in a gain saturation regime. In the period-doubling mode-locked(More)
We present a transportable effusive atomic beam apparatus for cascaded two-photon spectroscopy of the dipole-forbidden transition (6s(2)(1)S0↔ 6s7s (1)S0) of Yb atoms. An ohmic-heating effusive oven is designed to have a reservoir volume of 1.6 cm(3) and a high degree of atomic beam collimation angle of 30 mrad. The new atomic beam apparatus allows us to(More)