ガイライゴ ケンキュウ ニオケル イミ ブンセキ ムード ト フンイキ ノ ルイギ ブンセキ ニヨル ジレイ ケンキュウ

日本語は外来語の数が豊かであり、語彙全体における比重が高く、重要な役割を果たしている。外来語に関する先行研究も非常に活発になされてきたが、特に心理・社会的側面等から論じられることが多かった。しかし、外来語の研究が語彙の研究である以上、意味論的考察も重要な位置を占めなくてはならない。意味論的にみると、外来語とは必ずしもそれ以前から日本語の語彙の中に存在していた和語や漢語の単純な置き換えではない。本稿は外来語の意味的研究の一事例として、外来語「ムード」の意味特徴を漢語「雰囲気」との対比において明確にする。分析の結果、両語はそれぞれ次のような意味特徴を有していることを明らかにした。　「雰 囲気」の意味特徴：ある対象の、その部分の総和に還元できない全体から感じとられる性質。　「ム ード」の意味特徴：ある対象の、その部分の総和に還元できない全体から感じとられる、人間の情緒や感情に由来する性質。 すなわち、外来語「ムード」は他とは決して同一ではない独自の意味特徴を有し、その点に語彙における存在意義があることがわかる

Intracavity femtosecond-pulse compression with the addition of highly nonlinear organic materials

It is experimentally shown that using organic materials of high nonlinear refractive index dissolved in a saturable-absorber solution permits femtosecond-pulse compression in a simple colliding-pulse mode-locked laser employing cavity-mirror dispersion adjustment

A chirp-compensation technique using incident-angle changes of cavity mirrors in a femtosecond pulse laser

A technique for chirp-compensation in a CPM laser is presented. By using the change of the incident angle to multilayer dielectric cavity mirrors, the intracavity second-order dispersion φ^[・・] (ω) is adjusted without any additional elements. It is confirmed that the optimum value of φ^[・・](ω) = +2.1 x 10^[-28] s2 obtained when up-chirp was compensated and pulses as short as 55 fs were generated is reasonable, by comparison to analytic results of chirp behaviors. In addition, the effect of the third-order dispersion φ^[・・・] (ω) at the optimum value of φ^[・・] (ω) on pulses is evaluated

Analysis of a synchronously mode-locked and internally frequency-doubled CW dye laser

We present analytical studies of a synchronously modelocked and internally frequency-doubled CW (SMLFD) dye laser. The analysis describes the cavity detuning behavior of the pulse duration and the square of its peak intensity (the signal intensity of the autocorrelation trace) in terms of system parameters for different lengths of the intracavity crystal. The results predict the broadening of the pulse duration with the increase of the crystal length even though the condition of the group velocity matching is satisfied. It is shown that the prediction is in good agreement with the experimental results of the SMLFD rhodamine 6G laser with an ADP crystal in the cavity. Furthermore, the variation of the minimum pulse duration at the optimum cavity length as a function of the harmonic conversion efficiency is derived

Femtosecond-pulse laser chirp compensated by cavity-mirror dispersion

The duration of pulses generated from a simple colliding-pulse mode-locked cw dye laser is measured as a function of cavity-mirror dispersion. The optimum amount of mirror dispersion of Φ(ω) ≅ + 1.8 x 10^[-28] sec2 and a suitable mirror coating for upchirp compensation are identified. The adjustment of mirror dispersion only, without additional dispersive elements, generates continuous trains of pulses as short as 50 fsec

A compact synchroscan streak camera using a microchannel plate incorporated tube

A compact synchroscan streak camera, which incorporates a microchannel plates providing a high light gain, has been constructed. The camera has been operated in synchronism with a synchronous-passive hybrid mode-locked CW dye laser, and the overall time resolution has been 10.8 and 25.9 ps for a recording of ～160 and ～ lO^[8] cycles of dye laser pulses, respectively. In addition, by using the camera system with the dye laser a weak fluorescence profile (a quantum yield of ～10^[-3]) of an important biomolecule has been directly observed on a picosecond time scale

A single-photon sensitive synchroscan streak camera for room temperature picosecond emission dynamics of adenine and polyadenylic acid

It is experimentally verified that a synchroscan streak camera, incorporating a microchannel plate and synchronizing with UV picosecond pulses generated inside the cavity of a mode-locked CW ring dye laser, has enough sensitivity to detect picosecond emission phenomena in the region of a single-photon event. To demonstrate the usefulness of the synchroscan streak camera, the first measurement of time- and wavelength-resolved emissions in the picosecond region is successfully carried out for adenine and polyadenylic acid aqueous solutions at room temperature, and shows that their shortest lifetimes, due to the monomer fluorescence, are 6 and 8 ps, respectively