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1.
Direct measurements of the noise figure of an erbium-doped fiber amplifier are described. With an amplifier gain as high as 36 dB, a noise figure as low as 4.1 dB was measured. Noise figures remained below 6 dB for signal wavelengths within the high gain (G>20 dB) region of the amplifier. An optical receiver sensitivity of -43 dBm at 1.8 Gb/s, corresponding to 215 photons/b, was achieved using the fiber amplifier as an optical preamplifier for a direct detection receiver  相似文献   
2.
The performance of an eight-channel, 2.5 Gb/s OEIC photoreceiver array in an eight-wavelength long-distance WDM testbed is described. The sensitivity penalties due to crosstalk and transmission are measured, and the source of crosstalk is investigated. Channel sensitivities range from -25.4 to -26.2 dBm after transmission through 720 km of standard fiber, with transmission penalties ranging from 0.3 dB to 1.0 dB. When the power in each of seven interfering channels is 5 dB above sensitivity, the maximum crosstalk penalty suffered by an individual channel does not exceed 1 dB. These experiments are the first comprehensive characterization of monolithic receiver arrays for crosstalk performance under multichannel operation in a realistic system environment  相似文献   
3.
The authors demonstrate optical frequency tuning by direct electrical means as well as FM and AM mode-locking in an erbium-doped fiber laser with an intracavity distributed Bragg reflector active filter/modulator. They obtained a 6 nm discrete tuning range and pulses of 38 and 78 ps duration in AM and FM mode-locking, respectively  相似文献   
4.
Experimental and theoretical analysis of the gain dynamics of all-optically stabilized multichannel erbium-doped fiber amplifier (EDFA) and the impact on wavelength division multiplexed (WDM) networks performance requirements is presented. In particular, we focus on precise analysis of the detailed transient response of the surviving channel and the relaxation oscillations of the compensating (lasing) signal. The main objective of this work is to experimentally and theoretically analyze and examine some of the critical factors such as, lasing wavelength, gain recovery time, relaxation oscillation frequency of the feedback loop, and the number of channels dropped/added, that affect the transient power excursions in the surviving channel. First, we consider the applicability of laser automatic gain control (AGC) to control fast power transients in WDM optical networks and reports the first high resolution measurements of transients in such gain controlled EDFAs. Second, the experimental results are compared with those predicted from a numerical simulation of the dynamic of the gain controlled EDFA  相似文献   
5.
340 Gb/s (seventeen 20-Gb/s 231-1 PRBS NRZ channels) were transmitted through 150 km of fiber with 50 km amplifier spacing. Chromatic dispersion penalties and four-photon mixing effects were minimized by dispersion management  相似文献   
6.
The authors report the measured gain of a highly efficient erbium-doped fiber amplifier pumped at wavelengths between 1.46 and 1.51 μm. The optimal pump wavelength, λopt, was determined to be 1.475 μm. At this wavelength, the maximum gain coefficients for signals at 1.531 and 1.544 μm were 2.3 and 2.6 dB/mW, respectively. At λopt, high gains ranging from 32 dB at pump power Pp=20 mW up to 40 dB at P p=80 mW were obtained. These modest pump powers are within the capabilities of currently available 1.48-μm diode lasers. The width about λopt for 3-dB gain variation exceeded 27 nm for Pp=10 mW and 40 nm for Pp >20 mW. With this weak dependence on pump wavelength, single-longitudinal-mode lasers do not have a significant advantage over practical Fabry-Perot multimode pump lasers  相似文献   
7.
GaInAsSb/AlGaAsSb double heterostructure lasers with low pulsed threshold current density were grown previously by liquid-phase epitaxy using a complicated five-layer structure to relieve the strain arising from graded cladding layers. Double heterostructures have now been grown over a narrow temperature range to minimise this grading. These simpler three-layer DH lasers have high room-temperature quantum efficiencies (5.4% per facet) and low broad-area threshold current densities (2.6 kA/cm/sup 2/) which are uniform from chip to chip.<>  相似文献   
8.
Measurements and calculations of the GaInAsSb phase diagram near 530°C are reported. Epitaxial growth of compositions lattice-matched to GaSb is demonstrated over the range 0 ≤ x ≲ 0.22 before encountering the expected miscibility gap. Photoluminescence measurements yield bandgap energies from 0.73 eV for GaSb down to 0.53 eV at x = 0.22, indicating the potential application of these materials for optoelectronic devices operating at wavelengths between 1.71μm and 2.33μm. On leave from the Tata Institute of Fundamental Research, Bombay, India.  相似文献   
9.
Short single frequency erbium-doped fibre laser   总被引:3,自引:0,他引:3  
Very short erbium-fibre lasers with holographically written gratings in the erbium-doped fibre core are reported. An output power of 181 mu W was obtained from a 2cm long diode-pumped laser. A 1 cm long diode pumped laser had an output power of 57 mu W. As would be expected for such short cavity lengths, these lasers are robustly singlemode.<>  相似文献   
10.
In wavelength-division-multiplexing systems with optical amplifiers, channel drop or add can cause power changes in the existing channels. We present an analytical formula for the transient power of the existing channels as a function of time when one or more input channel is dropped or added on an erbium-doped fiber amplifier (EDFA). Although this formula was originally derived from perturbation theory of single-stage EDFA's, it is a good approximation of large-power excursion cases as well as two-stage EDFA's.  相似文献   
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