All issues
Volume 23, Issue 11
Displaying 1-14 of 14 articles from this issue
- |<
- <
- 1
- >
- >|
-
Takeshi KAMIYA1995 Volume 23 Issue 11 Pages 907
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDownload PDF (138K) -
Yuzo ISHIDA1995 Volume 23 Issue 11 Pages 908-921
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSSince a new mode-locking technique based on the Kerr nonlinearity in a laser rod wasdemonstrated for generation of highly stable and broadly tunable femtosecond pulses by asolid-state Ti: Al203 laser, experimental and theoretical studies on this technique have beenextensively developed. As a result, extremely short pulses, as short as 8 fs, were directly producedfrom the higher-order dispersion-compensated, self-mode-locked Ti: Al203 laser cavity. The tunable solid-state lasers have opened the door to the study of ultrafast quantum electronicsand related new fields.
This paper describes recent advances in the tunable femtosecond solid-state lasers including Kerr-lens mode-locking, solitary laser, effect of higher-order dispersion and compact LDpumpedlasers.View full abstractDownload PDF (1780K) -
Akira SHIRAKAWA, Takayoshi KOBAYASHI1995 Volume 23 Issue 11 Pages 922-927
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe generation of femtosecond pulses in the visible region by optical parametric conversionusing a KTiOPO4 crystal is reported. An optical parametric oscillator pumped by a mode-locked Ti: sapphire laser generates 81 MHz-femtosecond pulses tunable in the 426-483 nm and 529-585 nm regions by intracavity upconversion. The conversion efficiency is as high as 44%.View full abstractDownload PDF (752K) -
Nobuhiko SARUKURA, Zhenlin LIU, Yusaburo SEGAWA1995 Volume 23 Issue 11 Pages 928-935
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSVarious tunable ultraviolet lasers based on Ce-doped fluorides have been appeared recently.They have the vast possibilities as a new category of ultraviolet light sources, like Ti: sapphirelasers in infrared region. In this paper, we will review progresses in these laser materials.Here, we will also introduce our activities for the ultrafast laser application of these materialsincluding picosecond-pulse amplification using Ce: LuLiF4 (LLF) and Ce: LiCaAlF6 (LiCAF), and direct generation of short-pulse trains from Ce: LLF and Ce: LiCAF lasers using a newlyproposed, passive self-injection-seeding scheme.View full abstractDownload PDF (1109K) -
Takayoshi KOBAYASHI, Satoshi TAKEUCHI1995 Volume 23 Issue 11 Pages 936-944
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe generation of femtosecond pulses in the near-infrared with optical parametric conversionusing KTiOPO4 crystals are reported. Subpicosecond idler pulses tunable between 1.6and 3.0 μm are generated by parametric amplification with a Ti: sapphire regenerative amplifier. Idler pulses with a broad bandwidth up to 1300 cm-1 to be used as a probe in femtosecond pump-probe experiment are obtained by dispersion-free mixing and noncolinear phase matching.View full abstractDownload PDF (958K) -
Yoshinori SHICHIDA1995 Volume 23 Issue 11 Pages 945-953
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSRhodopsin, a photoreceptive protein in our eyes, is an excellent molecular switch to convertlight signal to the electrical response of the photoreceptor cells. Since the initial event of rhodopsin after absorption of a photon is a cis-trans isomerization of the retinylidene chromophore, elucidation of this isomerization mechanism has been a central issue in vision as wellas ultrafast spectroscopy. Recent progress of ultrafast spectroscopy enable us to elucidate theexcited state dynamics of rhodopsin; the Franck-Condon state has an extremely short lifetimeand converts to a fluorescent state, from which isomerization of the chromophore occurs.Chromophore isomerization is one of the fastest chemical reactions observed so far, andis achieved in the specific protein environment that have been constructed in the course ofanimal evolution.View full abstractDownload PDF (1246K) -
Takao FUJI, Noriaki TSURUMACHI, Toshiaki HATTORI, Hiroki NAKATSUKA1995 Volume 23 Issue 11 Pages 954-960
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSUltrafast spectroscopy with a white-light Michelson interferometer is explained. By using anincandescent lamp, it is possible to obtain femtosecond time resolution both in the linear (freeinduction decay) and nonlinear (photon echo) spectroscopy.View full abstractDownload PDF (767K) -
Kazunori NAGANUMA1995 Volume 23 Issue 11 Pages 961-972
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSHere we review the phase related measurements, that is, the dispersion measurement andthe pulse chirp measurement, which lay fundamental bases for the modern ultrafast optics. With an emphasis on the interferometric correlation methods, various methods are categorizedand compared. Recent advance in the dispersion-meter enables femtosecond group-delaymeasurements up to the laser cavity. For the pulse-form evaluation, novel methods using reconstruction algorithm can lead to the full-and detailed determination of the pulse electricfield.View full abstractDownload PDF (1471K) -
Toshio KATSUYAMA, Kensuke OGAWA, Kenji HIRUMA1995 Volume 23 Issue 11 Pages 973-980
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSNanometer-size free-standing GaAs whiskers are characterized by a sub-picosecond lasersystem. These whiskers can be grown by a reduced-pressure metal-organic vapor-phase epitaxy.Photoluminescence measurements of the GaAs whiskers show a spectral blue shift andalso a polarization anisotropy due to the two-dimensional quantum confinement of the carriers.However, the spectral blue shift is much smaller than the lowest level energy expectedby the square-potential confinement. This suggests the importance of the surface depletionpotential, which is inherently caused by the surrounding air. The influence of the surface layercan be clarified by the experiments on the surface recombination velocity of the whisker. Surfacetreatment with sulphur solution comfirms the importance of the surface state. The profileof the surface depletion potential can be estimated from the analysis of the recombinationrate. Thus the time-resolved photoluminescence measurement is quite useful for understandingthe surface state of the whisker.View full abstractDownload PDF (937K) -
Tetsuo HORIMATSU, Hajime IMAI1995 Volume 23 Issue 11 Pages 981-987
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPresent paper describes a transmission data format, called “Group Multiplexing and Coding, ” for ultra high-speed optical parallel interconnections and related devices. The potentiality of the format for solving skew and burst-mode compatibility problems is also presented.Our optical transmitter and receiver modules comprises a semiconductor laser diode arraywith a low threshold current, a photodiode with ultra-low parasitic capacitance, and arrayed LSICs fabricated by a GaAs submicron process. A 156 Mb/s-20 channel parallel transmissionexperiment over 400m shows that our transmission format solves skew and burst-mode compatibilityproblems in ultra high-speed optical transmissions.View full abstractDownload PDF (959K) -
Kazuhito TAJIMA, Shigeru NAKAMURA1995 Volume 23 Issue 11 Pages 988-995
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSWe experimentally demonstrate that the switching speed of a novel symmetric Mach-Zehnder (SMZ) all-optical switch, proposed by the present authors, is unrestricted by normally slow relaxation times of highly efficient, incoherent nonlinear refractions. A cross-correlation trace with a full-width at half-maximum of 2 ps was achieved, which is corresponding to nearly full-switching at 1.5 ps. To our best knowledge, this is the fastest switching experiment with incoherent and thus realistic nonlinearities. We also demonstrate that a repetition rate much faster than that implied by the relaxation time of the utilized optical nonlinearity is also possible with the SMZ all-optical switch. We will explain an experimental result under excitation by packets of four control pulses with a pulse interval of 100ps. We point out that the well-known figure of merit for optical nonlinear materials is no longer applicable to the present device and discuss how it is modified to take full advantage of the present device. We also note that a square-like, contrary to the exponential-like, switching characteristic is quite important in practice and show that such square-like modulation is possible with the SMZ all-optical switch.View full abstractDownload PDF (1015K) -
Shinichiro AOSHIMA, Haruyasu ITOH, Kazuyoshi KUROYANAGI, Yutaka TSUCHI ...1995 Volume 23 Issue 11 Pages 996-1001
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSWe have developed an all-solid-state femtosecond Cr: LiSAF laser that produces 44 fs pulses at an 87.6 MHz repetition rate with a 2.2 mW average power. The spectral width is 22 .4 nm and the peak wavelength is 906 nm. The time bandwidth product of 0.36 is obtained by assuming a sech2 waveform.View full abstractDownload PDF (614K) -
Yoko MIYAMOTO, Masahiro MATSUOKA1995 Volume 23 Issue 11 Pages 1002-1007
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe Gaussian noise burst model and the domain model for imperfectly mode-locked pulses are examined through comparison with two types of two-photon correlation experiments. These models are known to agree with autocorrelation measurements using nonlinear optical methods. The Gaussian noise burst model does not give correct results for the pulse-cycleaveraged, normalized second-order correlation function at zero time-delay, and the domain model fails to explain the two-component dip in coincidence count rate curves obtained with the interferometer configuration.View full abstractDownload PDF (632K) -
Yutaka KADOYA, Masamichi YAMANISHI1995 Volume 23 Issue 11 Pages 1008-1012
Published: November 30, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSWe 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.View full abstractDownload PDF (633K)
- |<
- <
- 1
- >
- >|