An optically pumped surface-normal optical amplifier with a 100-period InGaAs/InGaAlAs multiple quantum well is fabricated, and a signal gain exceeding 2 dB is observed for what we believe to be the first time. A laser diode with the wavelength lambda of 1.45 microm is used for pumping. An optical single-pass gain as high as 2.4 dB is obtained at lambda = 1.585 microm with 65-mW pumping (spot diameter 12 microm).
Gold (Au), silver (Ag), copper (Cu), and aluminum (Al) island films have been investigated for write-once optical data storage media with the high reflectance and the large reflectance changes induced by laser irradiation. We show that, of the four, the Ag and the Cu island films are the most useful as WO media at 800 nm. The Al island films are useful for a shorter wavelength region. The optical and structural changes in laser-written regions on the island films have also been investigated experimentally. It appears that the metal-island films show great potential as optical data storage media for compact-disk-compatible write-once optical disks.
Ultra-long span unrepeatered systems using distributed Raman amplification are cost-effective solutions for bridging moderate transmission distances. However, there are two major limiting factors: nonlinear Kerr effect-induced nonlinear signal distortion and optical signal-to-noise ratio degradation due to spontaneous Raman noise. In this report, we proposed a model of three-segment hybrid fiber effective core area structure and developed a model covering: (1) generalized mathematical formulations, (2) analysis of three-segment Raman amplified link, and (3) simulation model of data transmission. The proposed model showed an improvement of the Raman gain profile, a reduction of the negative impact of the nonlinear Kerr effect, and an enhancement of the optical signal-to-noise ratio. A numerical simulation of the transmission performance of the three-segment hybrid structure was compared to conventional single-segment single fiber core structure on 80 Gb/s differential quadrature phase-shift keying (DQPSK) modulated data signals over a propagation distance of 390 km. The required optical signal-to-noise ratio was reduced by 2.71 dB to achieve the target error rate without using forward error correction. The numerical model and simulation of various data rates up to 100 Gb/s consistently showed that an improvement in transmission performance could be achieved by using three-segment hybrid fiber effective core area structure.
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