Jung-Hee Han

Intensity noise suppression in spectrum-sliced incoherent light communication systems using a gain-saturated semiconductor optical amplifier

Using a gain-saturated semiconductor optical amplifier, we have suppressed the intensity noise in spectrum-sliced incoherent light communication systems. A large increase has been achieved in the signal-to-noise ratio that is much better than previous results to our knowledge. Using this technique, we have transmitted a 0.36-nm bandwidth 2.5-Gb/s incoherent light signal over 20 km of conventional single-mode fiber without any dispersion compensation. The transmission penalty was 1.5 dB and the error floor level was less than 10/sup -10/.

0.1-nm narrow bandwidth transmission of a 2.5-Gb/s spectrum-sliced incoherent light channel using an all-optical bandwidth expansion technique at the receiver

We introduce a new all-optical technique to transmit a spectrum-sliced incoherent channel with its optical bandwidth smaller than the conventional limit. As a demonstration, we reduce the optical bandwidth to only 0.1 nm for the 2.5-Gb/s incoherent channel transmission. Even though the signal-to-noise ratio (SNR) is poor during the transmission, sufficient SNR can be obtained through the intrachannel four-wave mixing at the receiver. With this slim bandwidth transmission technique, the maximum number of spectrum-sliced wavelength-division-multiplexed channels can be increased greatly and the dispersion penalty can be reduced simultaneously.

10-gigabit-per-second high-sensitivity and wide-dynamic-range APD-HEMT optical receiver

We report a 10-Gb/s hybrid APD-HEMT optical receiver employing a lossless tuned noise-matching technique between an APD and HEMT amplifier stages for high sensitivity and a transimpedance feedback scheme for the wide dynamic range. Measured results show a sensitivity of -29.4 dBm and a dynamic range of more than 29.4 dB, which are the best performances reported to date for 10-Gb/s APD-based optical receivers.

Transmission of 4 x 2.5-Gb/s spectrum-sliced incoherent light channels over 240 km of dispersion-shifted fiber with 200-GHz channel spacing

We demonstrate a transmission of 4/spl times/2.5-Gb/s spectrum-sliced incoherent wavelength-division-multiplexed channels over 240 km of dispersion-shifted fiber. The channel bandwidth and the channel spacing are kept small using the intrachannel four-wave mixing at the receiver. The error-floor level is close to 1/spl times/10/sup -11/ and the dispersion penalty is within 1 dB at 1/spl times/10/sup -9/ bit-error rate. Eye opening simulation shows that incoherent channels are less sensitive to the fiber four-wave mixing than coherent channels.

0.1-nm slim bandwidth transmission of a 2.5-Gbit/s spectrum-sliced incoherent channel using an all-optical bandwidth expansion technique at the receiver

Summary form only given. In this paper, we present a simple all-optical technique to reduce the optical bandwidth of the spectrum-sliced incoherent WDM channels. To minimize the dispersion penalty, the optical bandwidth is kept to a minimum value during the transmission. At the receiver side, we expand the signal bandwidth using the fiber four-wave mixing, which reduces the beat noise and restores the signal-to-noise ratio to a desired value.

4/spl times/2.5 Gbit/s transmission of spectrum-sliced incoherent light channels using an all-optical bandwidth expansion technique

Using an all-optical bandwidth expansion technique, we demonstrate the transmission of 4/spl times/2.5 Gbit/s incoherent WDM channels over a 240 km dispersion-shifted fiber. The channel power of incoherent WDM channels can be increased much higher than that of coherent channels near the zero-dispersion wavelength region.

2.5 Gb/s transmission of a spectrum-sliced incoherent hight source with 0.92 nm bandwidth over 80 km of dispersion-shifted fiber

We present a spectrum broadening technique to improve the signal-to-noise ratio of spectrum sliced incoherent light sources using the fiber four-wave mixing effect which occurs in a nonlinear loop mirror located at the receiver. The initial transmission channel bandwidth of 0.92 nm was increased to 1.62 nm in the nonlinear loop mirror at the optical receiver, which enhances the signal-to-noise ratio to a desired value. Using this technique, we have demonstrated the transmission of a 2.5 Gb/s NRZ signal with the 0.92 nm bandwidth through a 80 km dispersion-shifted fiber. The measured transmission penalty was less than 0.2 dB at

Transmission of directly modulated 2.5-Gb/s signals over 250-km of nondispersion-shifted fiber by using a spectral filtering method

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Suppression of intensity noise in 10 Gbit/s spectrum-sliced incoherent light channel using gain-saturated semiconductor optical amplifiers

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