Filter properties of chirped fiber Bragg grating Fabry-Perot cavity: a potential wavelength stabilizer of diode laser.

We investigate filter properties of chirped fiber Bragg grating (CFBG) (Fabry-Perot) F-P cavity through analyzing the coupled wave equation from one-dimensional Helmholtz equation. We derive an approximate formula of the reflectivity of a CFBG F-P cavity, simulate the central wavelength detuning, and calculate the central wavelength shift with the increase of ambient temperature. In the experiments, we measured the spectra of a diode laser with an FBG/CFBG F-P cavity at 0°C-110°C.

Tunable superstructure fiber Bragg grating with chirp-distribution modulation based on the effect of external stress.

We report an external stress modulation method for producing a superstructure fiber Bragg grating (FBG) with approximate cascaded resonant cavities composed of different index chirp distributions. The 15 mm uncoated apodized uniform-period FBG is pressed by the vertical stress from the upper 11 pieces of the pattern plate controlled by a piezoelectric ceramic actuator. The piece length is 1 mm, and the interval of the adjacent pieces is 0.

Study of back-scattering microspectrum for stomach cells at single-cell scale.

A fiber confocal backscattering (FCBS) spectrometer is developed based on fiber confocal microscopy and light scattering theory. The FCBS spectrometer can provide imaging and spectral information simultaneously at the cellular scale. Normal stomach epithelial cell line GES-1 and cancerous cell line NCI-N87 are measured and their spectral results show that backscattering intensity from NCI-N87 cells is stronger than that from GES-1 cells in 500 to 800 nm, and the GES-1 cells scattering spectra show regular intensity changes, while the NCI-N87 cells do not.

Small hairpin RNA targeting at Bcl-2 increases cytarabine-induced apoptosis in Raji cells.

Bcl-2, a prominent member of the Bcl-2 family proteins, is responsible for the dysregulation of apoptosis and resistance to chemotherapy. In this study, we investigated whether small hairpin RNA (shRNA) targeting at Bcl-2 mRNA could enhance cytarabine (Ara-C)-induced apoptosis in Raji cells. Bcl-2 shRNA was transfected into Raji cells and the expression levels of Bcl-2 mRNA and protein were assayed by RT-PCR and immunofluorescence.