All issues
Volume 27, Issue 11
Displaying 1-13 of 13 articles from this issue
- |<
- <
- 1
- >
- >|
-
Yasutomo FUJIMORI1999 Volume 27 Issue 11 Pages 733
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSDownload PDF (159K) -
Masakazu MORI1999 Volume 27 Issue 11 Pages 734
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSDownload PDF (169K) -
Yoshio CHO1999 Volume 27 Issue 11 Pages 735-743
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSMode-locking technique of lasers has its long history starting on quite early days of the advent of lasers. Pulse durations obtainable from mode-lock lasers were constantly shortened and reached femtoseconds today, roughly one-millionth from nano-second pulses at its beginning. In this tutorial review article, first, basic concept of mode-locking of lasers are described as its introduction, then putting emphasis on the topic of reducing the pulse duration, mode-lockings of solid-state lasers are mainly discussed. Control of the dispersion and the self-phase modulation inside the resonator, which is a key factor for obtaining ultra-short pulses, is described in detail.View full abstractDownload PDF (1729K) -
1999 Volume 27 Issue 11 Pages 743-743,749
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSDownload PDF (763K) -
Kenji TORIZUKA1999 Volume 27 Issue 11 Pages 744-749
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSRecent progress on mode-locked solid-state lasers in the femtosecond region is reviewed. Dispersiondesigned dielectric multilayer mirror is an ideal device to compensate the intra-cavity group-delay dispersion of the femtosecond mode-locked lasers. Semiconductor saturable absorber mirrors improve reliability of the mode-locked lasers without any pulse-broadening. With these two types of functional mirrors, stable sub-5fs optical pulse is generated directly from a Ti: sapphire laser oscillator.View full abstractDownload PDF (1407K) -
Hiroyuki YOKOYAMA1999 Volume 27 Issue 11 Pages 750-755
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSMonolithic and external-cavity mode-locked diode lasers (Mode-Locked Laser Diodes: MLLDs) are highly stabilized by means of electrical or optical signal injection incorporating a compact device module packaging. These MLLDs have potential applications in ultrahigh-speed optical communication and optical measurement systems. The MLLDs developed fully satisfy the requirements in a light source for the optical time division multiplexing (OTDM) communication scheme at 100 Gb/s rate. Instead of electrical hybrid mode-locking, subharmonic optical pulse injection can stabilize the MLLD operating at over 100 GHz. This technology will be useful for the generation of millimeter and sub-millimeter electromagnetic waves with optoelectronic conversion. Another notable feature of highly stable MLLDs is to provide pump and probe optical measurements with a simple system excluding mechanical optical-delay, that is to say the optical sampling. This optical sampling enables to observe 100 Gb/s rate optical data eye-pattern as well as precise temporalresponse of optical materials.View full abstractDownload PDF (1201K) -
Eiji YOSHIDA, Kohichi TAMURA, Masataka NAKAZAWA1999 Volume 27 Issue 11 Pages 756-761
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSMode-locking of fiber lasers is a useful technique for generating a high quality short pulse. An actively modelocked fiber laser which can emit short pulses at high repetition rates is one of the most attractive sources for realizing ultrahigh speed optical communications. This paper reviews femtosecond pulse generation from passively mode-locked fiber lasers. The fundamental characteristics and stabilization mechanisms of an actively mode-locked fiber laser are discussed. Lasing characteristics of the regeneratively mode-locked fiber in AM and FM operation are described.View full abstractDownload PDF (1001K) -
Kazuro KIKUCHI1999 Volume 27 Issue 11 Pages 762-767
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSThis paper describes the principle of ultra-short optical pulse measurement including novel measuremet methods that have recently been developed. The SHG auto-correlation method is most widely used to estimate the short optical pulse width. However, two-photon absorption in LED's and photodiodes has been applied to generate the nonlinear correlation signal instead of SHG, and has revealed remarkable performance in the short pulse measurement. On the other hand, the cross-correlation method such as the optical sampling method has been introduced into the measurement of transient response of optical devices and the pulse pattern measurement in ultra-high speed optical transmission systems. The reconstruction of the waveform and phase from the measured correlation signal is also an important problem. This paper deals with the FROG (Frequency Resolved Optical Gating) developed for this purpose.View full abstractDownload PDF (1002K) -
Kazuhiko YAMAGUCHI, Hitoki YONEDA, Kenichi UEDA1999 Volume 27 Issue 11 Pages 768-772
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSOptical refractive index of Yb-doped laser glass was measured with white light interferometer in which output beam was dispersed using a monochromater. The measured fringe spectrum was analyzed with compensating the amplitude modulation by the absorption. The estimated complex optical refractive index is better than 2×10-4 accuracy in absolute value and better than 2×10-5 in relative value in the wavelength range between 550 nm and 1160 nm. The feature of the anomalous dispersion due to Yb doped ion was clarified, quantitatively. This analysis denoted that in the case of Yb doped system, the contribution of the doped ions becomes dominant in the higher-order dispersion of refractive index. Thermal coefficient of this laser glass was also estimated from temperature dependence of refractive index from 293 K to 373 K. It was concluded that the excellent thermal stability of this laser glass was supported from the balance between negative thermo-optical coefficient and positive thermal expansion.View full abstractDownload PDF (788K) -
Kazuya KUMAGAI, Masayuki OKOSHI, Mitsugu HANABUSA1999 Volume 27 Issue 11 Pages 773-776
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSWe used 790-nm, 130-fs laser pulses for micromachining transparent materials including acrylic resin, quartz, diamond, and polyvinyl chloride. Using this technique, even 20 mm thick acrylic resin could bedrilled in 15 minutes, while a precise cut 20μm in width was produced in acrylic resin 0.5 mm thick. However, cracks were produced by the technique when used to drill or cut quartz plate. A 1-mm micro-gear was fabricated using acrylic resin.View full abstractDownload PDF (1302K) -
Tsuneo KURITA, Tomohiko ONO, Tsuyoshi NAKAI1999 Volume 27 Issue 11 Pages 777-781
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSThe final goal of this research is to construct a laser processing system to manufacture stepped shapes by utilizing detected processing sound. In order to achieve this goal, the basic investigations concern analyzing the relationship between laser processing characteristics and processing sound. The main purpose of this report is verify experimentally the possibility of monitoring the processed depth profile by using the value and fluctuation of the sound pressure level of processing sound. The main findings of this research are as follows: (1) The relationship between the depth of groove and sound pressure level can be represented by linear equation when Al2O3+TiC ceramic is used as the work material. (2) There exists a linear relationship between both fluctuations of bottom roughness of processed groove and sound pressure level when the laser energy per pulse is kept constant. (3) The depth profile of processed groove can be monitored by using processed sound.View full abstractDownload PDF (942K) -
Hiroyuki FURUKAWA, Norimitsu HIURA, Hiroki MATSUI, Takuji YOSHIDA, Hir ...1999 Volume 27 Issue 11 Pages 782-786
Published: November 15, 1999
Released on J-STAGE: March 17, 2010
JOURNAL FREE ACCESSA three dimensional (3D) analysis code of thermal birefringence in solid-state lasers was developed. Basic equations include thermal conduction, absorption of laser energy, thermal stress and thermal birefringence. Relative phase shifts induced by thermal effects measured and obtained by simulation are in good agreement with quantitatively. Edge effects of thermal birefringence are quantitatively estimated by 3D simulation. Those are unable to be estimated by 2D analysis.View full abstractDownload PDF (983K) -
Atsushi SHIMOURA, Takayasu MOCHIZUKI, Shuji MIYAMOTO, Sho AMANO, Tadao ...1999 Volume 27 Issue 11 Pages 787-789
Published: November 15, 1999
Released on J-STAGE: August 04, 2010
JOURNAL FREE ACCESSSoft x-ray spectra in the wavelength range of 3 to 18 nm from Ar, Kr, and Xe cryogenic targetsirradiated by 1-μm pulse laser at a laser intensity IL of 0.2 to 1.0×1012 W/cm2 have been observed. At a laser intensity of IL=1×1012W/cm2, the x-ray conversion efficiencies were 0.4%/sr/10%bw at the spectral peak of 3.2 nm for the Ar target, 0.7%/sr/10%bw at 10.0 nm for the Kr target, and 1.4%/sr/10%bw at 10.8 nm for the Xe target.View full abstractDownload PDF (429K)
- |<
- <
- 1
- >
- >|