Y. Nakata

1.55-μm Ce,Er:ZBLAN fiber laser operation under 980-nm pumping: experiment and simulation

Fiber laser operating property at 1.55-/spl mu/m band in a newly developed Ce,Er:ZBLAN fiber by a continuous-wave laser diode pumping at 980 nm is presented. The output characteristics of the Ce,Er:ZBLAN fiber laser system are analyzed in detail based on the rate equations model by taking into account the energy transfer between Ce/sup 3+/ and Er/sup 3+/ ions, as well as the upconversion mechanisms. The promotion role of the Ce in the erbium-doped ZBLAN for the 1.55-/spl mu/m band fiber laser operation has been realized.

Generation of new nanomaterials by interfering femtosecond laser processing and its electronic application

New nanomaterials such as nanobump array, nanomesh, nanobelt etc. were successfully generated by thin film processing using interfering femtosecond laser. Field emission from a nanobump array was firstly demonstrated.

Stimulated emission from ZnO nanorods synthesized by pulsed-laser deposition

We succeeded in synthesizing ZnO nanorods by pulsed-laser deposition (PLD) at comparatively high gas pressure without using any catalyst. Stimulated emission was observed from ZnO nanorods at 388 nm by optical pumping. It is found that nanoparticles formed in the gas phase play an important role in the nanorods growth.

Rate equation analysis of fluorescence characteristics of Er; Yb; Ce codoped ZBLAN glass

To improve 1.55 /spl mu/m band fluorescence, Ce and Yb were doped into Er doped ZBLAN glasses, the fluorescence characteristics and energy transfer dynamics of Ce:Er:Yb:ZBLAN glasses were investigated.

Fabrication of LiNbO/sub 3/ thin film by pulsed laser deposition and estimation of nonlinear property

LiNbO/sub 3/ thin films were deposited by pulsed-laser deposition (PLD) method. Crystalline and transparent films were deposited on sapphire substrate at 400 /spl deg/C and in 100 mTorr of oxygen gas pressure. The nonlinear property was measured by SHG experiment.

Fluorescence characteristics of Ce/sup 3+/, Yb/sup 3+/, Er/sup 3+/ doped fluorideglass for 1.55 /spl mu/m band

The fluorescence characteristics of Er/sup 3+/ codoped with Ce/sup 3+/ or Yb/sup 3+/ in ZBLAN glass were studied. It was found that the 1.55 /spl mu/m band fluorescence characteristics can be effectively improved by Ce/sup 3+/-codoping, and dynamics of the transfer and back transfer among Yb/sup 3+/ and Er/sup 3+/ ions in fluoride glasses can be well described by the energy transfer model.

Performance of tunable Ce/sup 3+/:Er/sup 3+/:ZBLAN fiber laser around 1.55 /spl mu/m

Fiber laser operation at 1.55 /spl mu/m band was first time realized in a Ce/sup 3+/:Er/sup 3+/:ZBLAN multimode fiber by cw LD pumping at 980 nm. The performance of wavelength tunable fluoride fiber laser around 1.55 /spl mu/m has been achieved.

Improved fluorescence characteristics of rare earth co-doping heavy-metal fluoride glasses for optical fiber amplifier

Er-doped heavy-metal fluoride glass, because of its wider emission bandwidth around 1500 nm, which spans the most important communications window, now has been investigated as one of the most promising materials for wide-band optical fiber amplifier, which would be of great value in the future wavelength division multiplexing (WDM) optical fiber communication system. However, one drawback of Er-doped fluoride glass is its low branching ratio leading to 1.55 /spl mu/m amplification under 980 nm excitation which is adopted for a low noise amplifier. Now this problem is expected to be solved by the rare earth co-doping technique. It has been proved that Ce co-doping into Er-doped fluoride glasses significantly improved the fluorescence quantum yield for the 1.55 /spl mu/m transition with 980 nm excitation. The Ce,Er co-doped fluoride glass is expected to be a new candidate material of a fiber amplifier for WDM.