H. R. Park

Design of a High Temperature Oven for Measuring the Saturation Intensity of Samarium atom by using Two Wave Mixing

We design a high temperature oven for measuring the saturation intensity of the transition line

Electromagnetic wave funneling through nano-gaps and nano-antennas

4f^ 6/6s^{2 7}7F_0 ↔ 4f^6/6s6p

Electrical Switching of Terahertz Radiation on Vanadium Dioxide Thin Film Fabricated with Nano Antennas

^1

Ultrabroadband metamaterial with full transmission control

P(J = 1)

Dielectric properties of a molecularly thin water layer in THz frequency range

of the samarium atom. We first constructed a high temperature oven to generate the samarium vapor column and study the thermal characteristics of the oven. The oven is able to operate at a temperature up to about 1400

Tight-binding description of transmission through crowded terahertz nanoresonators

^{circ}C

Resonance frequency shifts of rectangular holes on finite dielectric substrates

and the operation is tested by using several metals with high melting points. We describe two wave mixing experiment with the samarium vapor generated in the high temperature oven and obtain the saturation intensity by analyzing the first diffraction signal.

Pinch harmonic analogue of terahertz nanoresonator control using metal nanorods

We show that accumulation of charges at the metal edges via light-induced currents creates large horizontal electric field, which in effect attracts the incoming light. The enhanced field is fully propagating towards the far-field because no cut-off exists. With the amplitude enhancement in the range of 1,000, the intensity enhancement of 106, and the nonlinear enhancement of 1012, this structure can be an excellent launching pad for inducing broad-band nonlinearity, small signal detection in astronomy or biology, and for surface enhanced Raman scattering.

The polarization dependence of radiation trapping in the buffer gas environment

Electrical switching of terahertz radiation through nano antennas on VO2 thin film is demonstrated and is compared with bare VO2. Rectangular apertures act as slot antennas which attract terahertz radiation when VO2 is in semi‐conducting state. These antennas are turned‐off when VO2 becomes metallic by bias, giving an enhanced control of transmission.

Far field detection of terahertz near field enhancement of sub-wavelength slits using Kirchhoff integral formalism

We study log periodic nanoresonators on VO2 thin film, amplifying available dynamic range for extinction and transmission. Over 1,000:1 extinction ratio for the nano-pattern is achieved when the film undergoes insulator-to-metal phase transition, compared with 10:1 ratio for the unpatterned cases.