著者
斉藤 保典 キンブイ チャン デニス キリンジャー
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究
巻号頁・発行日
vol.22, no.3, pp.197-202, 1994

A 2.1 &mu;m &ldquo;eye-safe wavelength&rdquo;, 25mJ/pulse (A/O Q-switching), 90ns/pulse Ho lidar systemhas been developed to measure atmospheric extinction coefficients, &alpha;, and backscatter coefficients, &beta;. Range esolved values of &alpha; and &beta; were obtained at ranges covering up to 1.5km forsevera 124 hour periods. The average values of &alpha; were on the order of 10<SUP>-3</SUP> to 10<SUP>-4</SUP>m<SUP>-1</SUP> and &beta; values were estimated on the order of 10<SUP>-5</SUP> to 10<SUP>-6</SUP> m<SUP>-1</SUP> sr<SUP>-1</SUP>. The variation of &beta; as a function ofrange was small during the period from night to early morning, but increased significantly duringthe later daytime hours. The values of &beta; were somewhat higher from midnight to earlymorning than just after sunrise and then gradually decreased. &beta; values exhibited good correlation with the atmospheric humidity. From these observations it was confirmed that thelidar system developed is a powerful apparatus for remote sensing of the atmosphere.
著者
中沢 正隆
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.37, no.3, pp.171-176, 2009-03-15 (Released:2015-08-04)
参考文献数
16

optical transmission systems. Coherent quadrature amplitude modulation (QAM) is a very interesting
著者
荒川 泰彦 岩本 敏 西前 順一 菅原 充
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.47, no.4, pp.210, 2019 (Released:2021-08-13)
参考文献数
20

We overview progress in quantum dot (QD) lasers, emphasizing the advantage of the QD lasers for application to laser processing technology. Recent advances in our development of the QD lasers toward high quantum efficiency and high out power at the NEDO project are also discussed.
著者
白田 耕蔵
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.11, no.8, pp.568-575, 1983
被引用文献数
3

The laser-induced fluorescence (LIF) spectra for C<SUB>2</SUB> Swan system (d<SUP>3</SUP><I>&pi;</I><SUB>g</SUB>-a<SUB>3</SUB><I>&pi;</I><SUB>u</SUB>) were observed with an Ar<SUP>+</SUP> laser. Two laser lines of 472.7 and 514.5nm coincided with two ro-vibronic transitions: <I>R</I>(4) (<I>&Omega;</I>=2-2, =1-0) and <I>Q</I>(21) (<I>&Omega;</I>=2-2, <I>v</I>=0-0). The analysis yielded the vibrational parameters for the a<SUP>3</SUP><I>&pi;</I><SUB>u</SUB> electronic state. The observed LIF spectra could not be explained using the known parameters for the d<SUP>3</SUP><I>&pi;</I><SUB>g</SUB> electronic state. The parameters for the d<SUP>3</SUP><I>&pi;</I><SUB>g</SUB> state were redetermined through the reanalysis of the emission spectra for C<SUB>2</SUB> Swan system. The obtained parameters well explained the LIF spectra.
著者
霜田 光一
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.38, no.1, pp.10-12, 2010-01-15 (Released:2015-08-08)
参考文献数
6
被引用文献数
1

Development of the laser since its appearance in 1960 is reviewed. In the former 25 years after 1960
著者
竹内 延夫 杉本 伸夫 桜井 捷海 馬場 浩司 上野 敏行
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.11, no.10, pp.763-771, 1983
被引用文献数
1

Pseudo-random-modulation CW lider (RM-CW lider) is a new lider technique, which is essentially an optical version of the pseudo-noise (PN) radar. However, the crossover function is introduced to the RMCW lider in order to suppress the near-, distance strong-echo contribution. In his paper, RM-CW lidar is theoretically treated both in Mie-scattering lidar and differential absorption lidar (DIAL) cases. The fundamental performance of the former is experimentally demonstrated and the ability ofthe latter is discussed in a detailed case using an Ar laser as a transmitting laser.
著者
竹内 延夫 桜井 捷海
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.17, no.4, pp.320-328, 1989

A diode-laser random-modulation cw lidar (DL-RM-CW lidar) has an advantage of portability and versatility in handling. This paper reports examples of the npasurements of visibility and road dust dispersion by using the DL-RM-CW lidar.
著者
竹内 延夫 馬場 浩司 桜井 捷海 上野 敏行 井戸田 健 新井 敏弘 常見 真人 石河 直樹
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.13, no.4, pp.353-364, 1985

Random-modulation cw (RM-CW) lidar has characteristics that make it possible to use a small-power cw laser as the light source. Development of laser diodes (LD) has been very rapid recently. The laser diode is compact in size and can be driven with little energy compared with traditional lasers, so that it is the most promising candidate for use in a portable, compact and practical lidar system. In this paper, a prototype portable RM-CW lidar system with an LD light source is reported. This is the first report of a practical LD system, to the authors' knowledge. Measurements of the spatial aerosol profile up to several hundred meters, as well as cloud ceiling-height up to several kilometers, were detected, at night time with this system and are shown in this paper.
著者
石井 勝巳
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.40, no.12, pp.963, 2012 (Released:2020-08-26)
参考文献数
3

Recently, lasers are remarkably in use under various circumstances. The measurement of laser power and energy is the most fundamental one, and to know it quantitatively is very important for laser optimization by alignment, daily check as well as the min-max setting and the feedback system control in laser processing application, which leads to better quality control. So the interest in laser measurement is increasing more and more. In this paper I will pick up power meter and explain the principle, how to use and things to remember.
著者
平野 達
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.35, no.8, pp.486-492, 2007
被引用文献数
1

PDT is based on the generation of singlet oxygen (<SUP>1</SUP>O<SUB>2</SUB>) in a photochemical reaction among a tumor-accumulated photosensitizer, irradiation light, and oxygen in a tumor, and the detection of <SUP>1</SUP>O<SUB>2</SUB> is very important for understanding the mechanism of PDT. We used a near-infrared detection system to detect a 1270nm emission that was derived from the <SUP>1</SUP>O<SUB>2</SUB>. Utilizing this system, we detected the generation of <SUP>1</SUP>O<SUB>2</SUB> from Photofrin dissolved in water or injected in a HeLa tumor-bearing mouse. We showed the irradiation power dependence of the generation of <SUP>1</SUP>O<SUB>2</SUB> in 5-ALA-mediated PDT with 9L cells and 9L tumor-bearing rats. High-power irradiation reduced the generation of <SUP>1</SUP>O<SUB>2</SUB> more than that with low power, and an MTT assay revealed that more 9L cells were killed by low-powered irradiation. In tumors, low-powered irradiation resulted in efficient tumor necrosis. Generations of <SUP>1</SUP>O<SUB>2</SUB> in ICG and TiO<SUB>2</SUB> irradiation are also described.
著者
苗代 弘 和田 孝次郎 魚住 洋一 小林 弘明 竹内 誠 長谷 公洋 川内 聡子 佐藤 俊一
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.40, no.4, pp.265, 2012 (Released:2020-07-16)
参考文献数
17

Positive behavioral improvement has been observed following transcranial near-infrared light therapy in humans with chronic traumatic brain injury and acute stroke. We first examined the effect of 808 nm laser diode irradiation on regional cerebral blood flow (rCBF) in mice. An 808 nm CW diode laser was applied to the hemisphere transcranially. Transcranial near-infrared laser irradiation increased rCBF by 30% compared to control value in mice. Near-infrared laser irradiation also provoked a significant increase in cerebral nitric oxide concentration. In the clinical setting, transcranial near-infrared lightemitting diode irradiation to the forehead in a patient with persistent vegetative state following head injury was done. rCBF showed focal increase of 20%, compared to the pre-treatment value. The patient showed some improvement in his neurological condition after light-emitting diode therapy. Transcranial near-infrared irradiation might increase rCBF with some improvement of neurological condition in patients. Further study is warranted.
著者
ミラボー レイク
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.34, no.6, pp.423-428, 2006-06-15 (Released:2014-03-26)
参考文献数
24
被引用文献数
1 1

On 2 October 2000, a 12.2-cm diameter, 50.6-gram laser-boosted rocket Lightcraft flew to a new altitude record of 71-meters (233-ft) at White Sands Missile Range (WSMR) in New Mexico. The PLVTS 10-kW pulsed carbon dioxide laser, located on the High Energy Laser Systems Test Facility (HELSTF) powered the record flight, as well as six others-two of which reached 48.4-m (159-ft) and 56-m (184-ft). These were the first outdoor vertical, spin-stabilized flights of laser Lightcraft. Besides nearly doubling the previous altitude record of 39 meters (128-ft) set on 9 July '99, the Model #200 Lightcraft simultaneously demonstrated the longest laser-powered free-flight, and the greatest ‘air time’ (i.e., launch-to-landing/recovery). With a modest investment of under a million dollars, a string of ever-increasing Lightcraft altitude records have been set over the past four years-since the first flight on 23 April 1997. This embryonic, propulsion concept embodies “disruptive technology” that promises to radically transform our ideas about global flight transportation and space launch systems, over the next 15 to 25 years.
著者
小松 光昭 村田 雅人 木暮 信一
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.40, no.4, pp.285, 2012 (Released:2020-07-16)
参考文献数
17

This study clarifies the effect of low-power laser irradiation (LLI) on the muscle contraction of frog gastrocnemius and provides further insights into the possibility of clinical applications at the mammal level. When we used continuous wave LLI on the muscle contraction of frog gastrocnemius, the retardation of tension attenuation was obtained by near-infrared LLI (808 nm, 100 mW). However, we could not determine whether such retardation was based on the thermal or the photochemical effect of LLI. Since a pulsed laser has the potential to discriminate such effects, we conducted the present experiments. As a result, the pulsed LLI induced neither temperature increments nor retarded muscle fatigue. Although a thermal effect on the retardation of muscle fatigue cannot be excluded, we conclude that the photochemical action is dominant if the optical absorption and the temperature change of living tissue are considered.
著者
角屋 豊 山西 正道
出版者
一般社団法人 レーザー学会
雑誌
レーザー研究 (ISSN:03870200)
巻号頁・発行日
vol.23, no.11, pp.1008-1012, 1995

We have demonstrated that the exciton-polariton mode splitting in semiconductor microcavities can be continuously altered in a wide range, from its maximum to zero, through the change in the exciton oscillator strength. This has been achieved by making use of a quantum confined Stark effect together with angle tuning of the cavity mode. On the basis of the ex-perimental results, we point out a possibility of THz electromagnetic wave radiation from the oscillating dipole associated with the cavity-polariton in biased semiconductor microcavities.