A 2.5W superfluorescent fiber source (SFS) and a tunable PCF laser with 74.4 nm tuning range and 5.5 W output power
are experimentally demonstrated by utilizing an ytterbium-doped photonic crystal fiber (PCF) as the gain medium. The
tunable operation of the laser is realized by rotating a diffraction grating. Effects of the degrees of the cleaved angle at
the anti-reflection fiber end on the output characteristics of the laser and the SFS are investigated. A large cleaved angle
is beneficial to realize a broad laser tuning range and beneficial to obtain a high power superfluorescent fiber source
without parasitic lasing.
Thermal properties and spectroscopic properties of the glass micro-sphere were presented in this paper. The Er<sup>3+</sup> emission
spectra of a kind of Erbium-doped glass microsphere were measured and discussed under 532nm excitation in a series of
temperatures. The change in the temperature of the microsphere leads to a change in both the size and the index of
refraction of the sphere, which results in the resonance shift of the peaks of whispering gallery modes in emission spectra.
The temperature of the environment surrounding the sphere can be determined by monitoring the shift, which allows us to
calibrate the sensing function of the shift proportional to temperature. Based on the thermal effects, we propose a novel
optical temperature sensor using micrometer-sized sphere.
We investigate the influence of particle plasmon resonance of Au nanoislands structures on the exciplex emission in the
polymer blend of poly (9, 9'-dioctylfluorene-co-benzothiadiazole) (F8BT) and poly (9,9'-dioctylfluorene-co-bis-N,N'-
(4-butylphenyl)-bis-N,N'-phenyl-l,4-phenylenediamine) (PFB). The experimental results indicate that when the particle
plasmon resonance of the gold nanoisland structures overlaps the spectral range of the exciplex emission, significant
enhancement of the photoluminescence can be observed. Furthermore, longer lifetime has been measured for the
red-shift emission of the exciplex. We proposed that the localized field due to the particle plasmon resonance of the Au
nanoislands has modulated the mechanisms for the formation of exciplex, which may be related to the exciton diffusion,
charge transfer, and phase separation at the interface between the two materials.
The silicate glass micro-particles of co-doped with Er<sup>3+</sup> and Yb<sup>3+</sup> were prepared by a combustion process and
characterized from the spectroscopic point of view, with the aim of investigating the effect and mechanisms of
upconversion emissions. The upconversion emissions at 522nm and 547nm have been obtained by exciting the silicate
glass micro-particle [about 30μm in diameter] under 976nm diode laser excitation. The excitation intensity was up to
about 1800W/cm<sup>2</sup>. It was observed that the intensity ratio of the 522-nm emission to the 547-nm emission (I<sub>522nm</sub>/I<sub>547nm</sub>)
in silicate glass increased when increasing the excitation intensity. I<sub>522nm</sub> became larger than I<sub>547nm</sub> when the excitation
intensity was above 300W/cm<sup>2</sup>. It is proposed that the phenomenon resulted from the rise of the temperature of the
In this paper, the glass microsphere co-doped Er<sup>3+</sup>/Yb<sup>3+ </sup>was fabricated. Many regularly spaced, sharp peaks
appeared in the emission spectra of the glass microspere. We report the laser power induce the spectral shift of the
whispering-gallery-modes [WGMs] of a glass sphere. The laser power dependence of the WGMs spectral position is
about 0.0252nm/mW under 976nm excitation. Maybe, the glass microsphere can be used as a temperature sensor.
In this work, The TiBa glass microspheres doped with Tm<sub>2</sub>O<sub>3</sub> for optical resonances of up-conversion emission were designed and preparation. The components of the glass sample are 25TiO<sub>2</sub>-27BaCO<sub>3</sub>-8Ba(NO<sub>3</sub>)<sub>2</sub>-6ZnO<sub>2</sub>-9CaCO<sub>3</sub>- 5H<sub>3</sub>BO<sub>3</sub>-10SiO<sub>2</sub>- 9water glass-1Tm<sub>2</sub>O<sub>3</sub> (wt.%). The emission spectra of the TiBa matrix glass and the TiBa glass microspheres under 633nm excitation were measured. The up-conversion emission bands appeared at around 480nm. Many regularly spaced, sharp peaks appeared in the emission spectra of a Tm<sup>3+</sup>-doped glass microsphere . The observed resonances could be assigned by using the well-known Lorenz-Mie Formalism.
Micro-Raman spectra of four annealing Cd<SUB>1-y</SUB>Zn<SUB>y</SUB>Te crystal samples with small concentrations were measured within the spectral range of 40cm<SUP>-1</SUP> to 500cm<SUP>-1</SUP>. Three main Raman scattering peaks were found in all four samples and that the Raman peaks in the samples get higher and narrower with longer annealing time. Strong photoluminescence in the four samples also were observed, which come from the band edge radiation. The composition value y of Cd<SUB>1-y</SUB>Zn<SUB>y</SUB>Te crystals can be easily calculated by using these micro-photoluminescence peaks.
Structural resonances have been found in the Raman spectrum of an optically levitated TiBa glass microsphere. The observed resonances could be assigned by using the well-known Lorenz-Mie Formalism. It was found that the diameter of the TiBa glass microsphere is 24.490micrometers , and the refractive index of TiBa glass is 1.895 at about 645nm.