1,721,025 research outputs found
o-Orsellinaldehyde from the submerged culture of the edible mushroom Grifola frondosa exhibits selective cytotoxic effect against Hep 3B cells through apoptosis
No full textSingle polarisation operation of a Nd<sup>3+</sup>-doped single-mode fiber laser
No full textAs a laser source, single-polarization fiber lasers are of considerable interest for many potential sensor applications. The fiber lasers reported to date have had essentially unpolarized outputs due to the difficulty of including intracavity polarization control components such as Brewster windows in the compact cavity of the fiber laser. Using a recently developed technique, we incorporated a low-loss high-extinction-ratio single-mode fiber polarizer into the cavity of a Nd3+-doped fiber laser. This technique exploits the interaction of the evanescent field of the lasing mode with a short length of metal embedded in the cladding of the fiber
Polarisation effects in fibre lasers : phenomena, theory and applications
No full textSingle-mode fibre lasers play a important role in optical fibre communications and sensors. They exhibit a number of interesting phenomena, one of the most important being polarisation effects, which have not yet been properly evaluated
Modeling of polarization effects in fiber lasers
No full textExperimental investigation of various fiber lasers containing rare earth ions shows that the polarization effects with a Fabry-Perot cavity can be characterized by three basic factors: The fluorescence caused by spontaneous emission is depolarized independently of the polarization of the pump light. Two orthogonal phase independent polarization eigenmodes exist in the single-mode fiber laser cavity. The polarization state of the output from the fiber laser depends on the orientation of the pump light polarization, pump power level, and dopant characteristics. The evidence of polarization effects in a Nd3+ doped fiber laser can be clearly seen from Figs. 1 and 2 and Ref. 1
Single-polarisation fibre laser incorporating an in-line metal polariser
No full textFor many applications the realisation of a practical single polarisation singlemode (SPSM) fibre laser is of considerable interest. In this paper we report an in-line metal-plated fibre polariser technique for making SPSM fibre lasers. The corresponding theory, design method and experimental results are also presented
A diode pumped single-mode fibre laser
No full textFibre lasers present numerous advantages over other lasers not only in terms of low threshold, efficiency and low operating power but also with respect to their compatibility with standard single-mode fibres. Lasing action has been demonstrated in rare-earth doped silica single-mode fibres with both semiconductor laser and argon ion/dye laser pump sources. Semiconductor laser-diode pumping is highly convenient both in terms of cost and operational requirements. We describe here the characteristics of a single-mode Nd3+-doped fibre laser operating at 1.088µm. In particular results are presented for CW, Q-switched and mode-locked operation
Polarisation effects in fibre lasers
No full textTwo orthogonal polarisation eigenmodes have been observed in a single-mode fibre laser. Experimental investigation shows good agreement with theoretical analysis. Both Nd3+ and Er3+-doped single-polarisation single-mode fibre lasers have been demonstrated
Single polarisation fibre lasers using an integral polariser
No full textFibre lasers represent a new class of active fibre devices with considerable potential for use in telecommunications, sensors and laboratory measurements. For these applications the realisation of a practical single-polarisation single-mode (SPSM) fibre laser is of considerable interest. In this paper we report an integral fibre polariser technique for making SPSM fibre lasers. The corresponding theory, design method and experimental results are also presented. It is shown that it is far more efficient to use an intra-cavity polariser than to polarise the output light with an external polariser
A simultaneously Q-switched and mode-locked fibre laser
No full textGiant and ultrashort pulse operations of laser devices play an important role in both physics and engineering. The Q-switched operation and mode-locked pulses from fibre lasers have been being of great interests since single-mode fibre lasers were developed. In this paper we report (1) the first observation of repetitive self-pulsing of a fibre laser, (2) the first demonstration of an all-fibre self-pulsed and diode-locked fibre laser, and (3) a simultaneously Q-switched and mode-locked fibre laser modulated at the Q-switching frequency
Photon-injection polarisation-switching in fibre lasers
No full textA novel photonic switching device based on polarisation switching by optical injection in fibre lasers is investigated. An all-optical switching device with an extremely low threshold (0.1µW) has been demonstrated. The mechanism of operation, experimental realisation and device characteristics are presented
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