다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Fibre lasers in the mid-infrared regime are useful for a diverse range of fields, including chemical and biomedical sensing, military applications and materials processing. This Review summarizes the different rare-earth cations and host materials used in mid-infrared fibre laser technology, and discusses the future applications and challenges for the field.

Towards high-power mid-infrared emission from a fibre laser

Infrared (2–12 μm) solid-state laser sources: a review

Fiber lasers have seen progressive developments in terms of spectral coverage and linewidth, output power, pulse energy, and ultrashort pulse width since the first demonstration of a glass fiber laser in 1964. Their applications have extended into a variety of fields accordingly. In this paper, the milestones of glass fiber laser development are briefly reviewed and recent advances of high-power continuous wave, Q-switched, mode-locked, and single-frequency fiber lasers in the 1, 1.5, 2, and 3 μm regions and their applications in such areas as industry, medicine, research, defense, and security are addressed in detail.

Fiber lasers and their applications [Invited]

In this review we discuss the application of laser-induced breakdown spectroscopy (LIBS) to the problem of detection of residues of explosives. Research in this area presented in open literature is reviewed. Both laboratory and field-tested standoff LIBS instruments have been used to detect explosive materials. Recent advances in instrumentation and data analysis techniques are discussed, including the use of double-pulse LIBS to reduce air entrainment in the analytical plasma and the application of advanced chemometric techniques such as partial least-squares discriminant analysis to discriminate between residues of explosives and non-explosives on various surfaces. A number of challenges associated with detection of explosives residues using LIBS have been identified, along with their possible solutions. Several groups have investigated methods for improving the sensitivity and selectivity of LIBS for detection of explosives, including the use of femtosecond-pulse lasers, supplemental enhancement of the laser-induced plasma emission, and complementary orthogonal techniques. Despite the associated challenges, researchers have demonstrated the tremendous potential of LIBS for real-time detection of explosives residues at standoff distances.

Laser-induced breakdown spectroscopy for detection of explosives residues: a review of recent advances, challenges, and future prospects

NASA Langley Research Center has a long history of developing 2-micron laser transmitter for wind sensing. With support from NASA Laser Risk Reduction Program (LRRP) and Instrument Incubator Program (IIP), NASA Langley Research Center has developed a state-of-the-art compact lidar transceiver for a pulsed coherent Doppler lidar system for wind measurement. This lidar system was recently deployed at Howard University facility in Beltsville, Maryland, along with other wind lidar systems. Coherent Doppler wind lidar ground-based wind measurements and comparisons with other lidars and other sensors will be presented.

https://ntrs.nasa.gov/api/citations/20090037581/downloads/20090037581.pdf

Wind Profiling from a New Compact, Pulsed, 2-Micron, Coherent- Detection Doppler Lidar Transceiver during Wind Measurement Intercomparison

A new project, selected in 2005 by NASA's Science Mission Directorate (SMD), under the Instrument Incubator Program (IIP), will be described. The 3-year effort is intended to design, fabricate, and demonstrate a packaged, rugged, compact, space-qualifiable coherent Doppler wind lidar (DWL) transceiver capable of future validation in an aircraft and/or Unmanned Aerial Vehicle (UAV). The state-of-the-art 2-micron coherent DWL breadboard at NASA/LaRC will be engineered and compactly packaged consistent with future aircraft flights. The packaged transceiver will be integrated into a coherent DWL system test bed at LaRC. Atmospheric wind measurements will be made to validate the packaged technology. This will greatly advance the coherent part of the hybrid DWL solution to the need for global tropospheric wind measurements.

https://ntrs.nasa.gov/api/citations/20080014319/downloads/20080014319.pdf

Compact, Engineered, 2-Micron Coherent Doppler Wind Lidar Prototype for Field and Airborne Validation: Doppler Aerosol WiNd Lidar (DAWN). Interim Review #1 (6 months)

A pump-probe setup capable of directly measuring the upper laser level population dynamics of the 5I7 → 5I8 laser transition is developed taking advantage of the strong ground-state depletion. This pump-probe experiment first is used to investigate the spatial distribution of the pump intensity in a laser-diode side-pumped laser crystal, then to determine the main energy transfers involved in Ho:Tm systems and also to estimate the intrinsic optical losses of the laser crystal. Finally, using the results of this pumpprobe experiment we were able to precisely simulate the performance of a laser-diode side-pumped Ho:Tm YLiF4 2μm laser.

Direct measurement of upper laser level population dynamics in a laser-diode side-pumped Ho:Tm:YLiF4 2µm laser

115-mJ Q-switched laser pulses with the pulsewidth of about 150 ns were generated by a Tm:Ho:LuLF laser oscillator and 626-mJ laser pulses were demonstrated by Tm:Ho:LuLF master-oscillator-power-amplifiers (MOPA) consisting of one oscillator and two amplifiers.

600 mJ Q-switched diode-pumped Tm:Ho:LuLF master-oscillator-power-amplifiers (MOPA) at 2.05 /spl mu/m

An airborne 2 micron triple-pulse integrated path differential absorption (IPDA) lidar is currently under development at NASA Langley Research Center (LaRC). This lidar targets both atmospheric carbon dioxide (CO2) and water vapor (H2O) column measurements, simultaneously. Advancements in the development of this IPDA lidar are presented in this paper. Updates on advanced two-micron triple-pulse high-energy laser transmitter will be given including packaging and lidar integration status. In addition, receiver development updates will also be presented. This includes a state-of-the-art detection system integrated at NASA Goddard Space Flight Center. This detection system is based on a newly developed HgCdTe (MCT) electron-initiated avalanche photodiode (e-APD) array. Future plan for IPDA lidar system for ground integration, testing and flight validation will be discussed.

/pdf/progress-on-development-of-an-airborne-two-micron-ipda-lidar-11pfu5bwqa.pdf

Jirong Yu

Papers

Wind Profiling from a New Compact, Pulsed, 2-Micron, Coherent- Detection Doppler Lidar Transceiver during Wind Measurement Intercomparison

Compact, Engineered, 2-Micron Coherent Doppler Wind Lidar Prototype for Field and Airborne Validation: Doppler Aerosol WiNd Lidar (DAWN). Interim Review #1 (6 months)

Direct measurement of upper laser level population dynamics in a laser-diode side-pumped Ho:Tm:YLiF4 2µm laser

600 mJ Q-switched diode-pumped Tm:Ho:LuLF master-oscillator-power-amplifiers (MOPA) at 2.05 /spl mu/m

Progress on development of an airborne two-micron IPDA lidar for water vapor and carbon dioxide column measurements