Performance of a high concentration Er/sup 3+/-doped alumino silicate fiber amplifier

We report the gain, noise figure, output saturation power, and conversion efficiency of a highly concentrated Er/sup 3+/-doped alumino silicate fiber amplifier. We obtain a gain per unit length of 1.0 dB/cm, which corresponds to the highest gain per unit length obtained in an Er/sup 3+/-doped fiber amplifier. The pump power threshold ranges from 2 to 5 mW, depending on the fiber length.     

All-fiber active add-drop wavelength router

We describe a fiber Bragg grating Mach-Zehnder interferometer (FBG-MZI) which utilizes active phase control. The active FBG-MZI is operated as a wavelength router, where the grating-selected wavelength channel can be actively routed. We believe this is the first demonstration of an all fibre FBG-MZI wavelength router.     

Concentration-dependent 4I13/2 lifetimes inEr3+-doped fibers and Er3+-doped planar waveguides

We report on the concentration- and pump-dependent lifetimes of the spontaneous emission in Er³⁺-doped fibers and Er³⁺ -doped waveguides. In addition, we measure the concentration dependence of the 550-nm fluorescence due to excited state absorption (ESA)     

A wavelength-tunable curved waveguide DFB laser with an integratedmodulator

A distributed-feedback (DFB) laser with a curved waveguide in the active region integrated with an electroabsorption modulator is studied experimentally and theoretically. The modulator controls the lasing wavelength of the DFB laser by acting as an optical phase shifter. Our model, which is based on the transfer matrix method, is used to simulate this multisection device with the curved waveguide, self-consistently including the effects of spatial hole burning (SHB). The model explains the features and wavelength-tuning behavior of the spectrum and shows good agreement with experimentally measured spectra. We also show theoretically that the curved waveguide suppresses the longitudinal photon density profile of the device compared with a straight waveguide case, which implies reduced SHB effects     

An erbium-doped multimode optical fiber amplifier

The authors describe the first experimental study of an erbium-doped multimode fiber amplifier. The focus has been to characterize an intermediate core erbium-doped optical fiber, a fiber that is capable of propagating many guided modes at both the signal and pump wavelengths, and to determine the feasibility of using such an active fiber as a multimode fiber amplifier, by measuring its gain, noise, and pump power requirements. For a 2-m length of a 13-μm-core erbium-doped fiber, the authors measured gain as high as 16 dB at a signal wavelength of 1543 nm, with approximately 100 mW pump power (980 nm). For these same test conditions, the smallest excess noise factor β was 42     

Elimination of self-contamination in high-density low-loss single-mode fiber array connectors

We report quantitative measurements of self-contamination in conventional and modified multi-SMF mechanically transferable (MT) connector ferrules. The modifications enable connector wear, insertion loss (IL), and IL reproducibility that are essentially equivalent to conventional ceramic ferrule connectors.     

8-mV threshold Er/sup 3+/-doped planar waveguide amplifier

We report on the gain characteristics of a low threshold (8 mW) Er/sup 3+/-doped planar optical waveguide amplifier. Net fiber to fiber gain of 4.5 dB is achieved at a signal wavelength of 1536 nm with 80 mW of 980-nm pump power. This device represents significant progress toward a planar amplifier module pumped by a single laser diode.     

Systems evaluation of an Er3+-doped planar waveguideamplifier

We report the output saturation power, excess noise factor, and system performance of a highly concentrated Er³⁺-doped planar optical waveguide amplifier. The performance data demonstrate the potential usefulness of planar optical waveguide amplifiers in system applications