• Current Optics and Photonics
• /
• 제6권6호
• /
• pp.576-582
• /
• 2022

Plasmonic high-order harmonic generation (HHG) is used in nanoscale optical applications because it can help in realizing a compact coherent ultrashort pulse generator on the nanoscale, using plasmonic field enhancement. The plasmonic amplification of nanostructures induces nonlinear optical phenomena such as second-order harmonic generation, third-order harmonic generation, frequency mixing, and HHG. This amplification also causes damage to the structure itself. In this study, the plasmonic amplification according to the design of a metal-coated sapphire conical structure is theoretically calculated, and we analyze the effects of this optical amplification on HHG and damage to the sample.

• 한국광학회:학술대회논문집
• /
• 한국광학회 1998년도 제15회 광학 및 양자전자 학술발표회 논문집
• /
• pp.68-69
• /
• 1998

• 한국전기전자재료학회논문지
• /
• 제16권9호
• /
• pp.833-837
• /
• 2003

The spectral and temporal characteristics of a V-groove AIGaAs-GaAs quantum wire (QWR) laser were investigated with varying the cavity length. At cavity lengths shorter than 300 ${\mu}{\textrm}{m}$, a discrete shift in tile wavelength occurred from the n=1 to the n=2 subband due to the increased cavity losses. Utilizing this characteristic, ultrafast lasing characteristics at each subband were investigated by tile gain switching method.

• Journal of the Optical Society of Korea
• /
• 제13권1호
• /
• pp.80-85
• /
• 2009

An experimental study of energy absorption and x-ray emission from ultrashort laser pulse irradiation of in-situ produced solid clusters has been performed. Silver clusters produced by a 30 mJ, 300 ps laser pulse were irradiated up to an intensity of $3{\times}10^{17}\;W/cm^2$ by a 70 mJ, 45 fs compressed laser pulse from the same Ti:sapphire laser. Absorption of the laser light exceeding 70% was observed, resulting in an x-ray yield (>1 keV) of ${\sim}60{\mu}J$ pulse. This may constitute a much simpler means of intense x-ray generation using ultrashort laser pulses as compared to the irradiation of structured / pre-deposited cluster targets, and it offers higher x-ray conversion efficiency than that from gas clusters and planar solid targets.

• 전기전자학회논문지
• /
• 제9권2호
• /
• pp.115-122
• /
• 2005

모드잠금 고리형 광섬유 레이저 출력의 단열 쏠리톤 펄스압축에 의해 $1545{\sim}1550\;nm$ 파장영역에서 400 ??토초의 안정성이 뛰어난 변환제한급의 10 GHz의 광 펄스를 발생시켰다. 특별한 슈퍼모드 선택소자를 사용하지 않고도 -123 dB/Hz 이하의 슈퍼모드 비팅 잡음 억제에 의해 $1\;kHz{\sim}100\;MHz$의 잡음대역에서 100 ??토초 미만의 낮은 시간 지터를 얻었다.

• 한국광학회지
• /
• 제15권3호
• /
• pp.278-284
• /
• 2004

지속시간이 펨토초 수준에 이르는 빛펄스의 전기장 및 위상의 시간적 변화를 잴 수 있는 "이차조화파 발생 프로그(SHG FROG: Second Harmonic Generation Frequency Resolved Optical Gating)" 장치 및 소프트웨어를 개발하고 성능을 확인하였다. 이 장치를 써서 잰 실험값으로부터 빛펄스를 복원하는데는 "주요성분 일반 투영(PCGP: Principal Component Generalized Projection)" 방식에 더하여 프로그 궤적의 주파수 및 시간지연 "한계값(marginal)"과 이차조화파의 분광분포에 대한 조건을 덧붙임으로써 복원과정의 안정성과 수렴속도를 개선하였다.

• 한국광학회지
• /
• 제5권4호
• /
• pp.466-472
• /
• 1994

아르곤 레이저에 의해 광펌핑 되는 티타늄 사파이어 레이저를 제작하고 이를 자체 모드록킹 시켰다. 모드록킹은 볼 슬라이더 위에 장착된 공진기 거울의 이동에 의해 시작되었으며 티타늄 사파이어 결정내의 자체 집속 효과와 공진기내에 설치된 조리개에 의해 모드록킹이 유지 되었다. 공진기내의 군속도를 보상하기 위하여 프리즘쌍을 사용하였으며, 모드록킹된 펄스의 대역폭은 11nm, 펄스폭은 $1000\pm20fs$였다.

• Journal of the Optical Society of Korea
• /
• 제13권1호
• /
• pp.8-14
• /
• 2009

In a laser-plasma wakefield accelerator, the ponderomotive force of an ultrashort high intensity laser pulse excites a longitudinal wave or plasma bubble in a way similar to the excitation of a wake wave behind a boat as it propagates on the water surface. Electric fields inside the plasma bubble can be several orders of magnitude higher than those available in conventional RF-based particle accelerator facilities which are limited by material breakdown. Therefore, if an electron bunch is properly phase-locked with the bubble's acceleration field, it can gain relativistic energies within an extremely short distance. Here, in the bubble regime we show the generation of stable and reproducible sub GeV, and GeV-class electron beams. Supported by three-dimensional particle-in-cell simulations, our experimental results show the highest acceleration gradients produced so far. Simulations suggested that the plasma bubble elongation should be minimized in order to achieve higher electron beam energies.