Yun Chung - Profile on Academia.edu (original) (raw)

Papers by Yun Chung

Effect of polarization-dependent loss on optical signal-to-noise ratio monitoring technique based on polarization-nulling method

Optics Express, 2006

We analyzed the probability of errors in the measured optical signal-to-noise ratio (OSNR) by usi... more We analyzed the probability of errors in the measured optical signal-to-noise ratio (OSNR) by using the polarization-nulling method, when the amplified spontaneous emission noise (ASE) is partially polarized due to the polarization-dependent loss (PDL) in the transmission link.

Quantum Limited Atomic Resonance Optical Filter

PhDT, Sep 1, 1987

Next-generation WDM PON technologies

Asia Communications and Photonics Conference and Exhibition, Dec 1, 2010

We report our recent progresses toward the next-generation wavelength-division-multiplexed passiv... more We report our recent progresses toward the next-generation wavelength-division-multiplexed passive optical network (WDM PON) including the high-speed (>;10 Gbps) and long-reach (>;100 km) operations.

Performance monitoring techniques for WDM networks

This paper reviews the current status of various optical monitoring techniques for WDM networks w... more This paper reviews the current status of various optical monitoring techniques for WDM networks with an emphasis on the OSNR monitoring technique. The results show that the polarization-nulling technique could be used in modern dynamic WDM networks and enhance their operation and maintenance.

IEEE Photonics Technology Letters, Sep 1, 1996

IEEE Photonics Technology Letters, Jun 1, 1992

We report a simple ZnS etalon filter tunable with temperature (5 GHz/"C) for channel selection an... more We report a simple ZnS etalon filter tunable with temperature (5 GHz/"C) for channel selection and noise filtering in amplified WDM systems. It has large free-spectral-range (30 nm), narrow passband (4.6 A), and low insertion loss (1 dB). The filter has been used for channel selection in a WDM system without any degradation in the receiver sensitivity. When the filter was locked to a desired channel using a simple digital servoloop, it maintained a very stable transmission (maximum drift < 3%) even when the wavelength of transmitter laser was intentionally changed by as much as 1 nm.

Electronics Letters, Aug 18, 1994

The authors have demonstrated I .7Ghitls transmission over I65 km of dispersion-shifted fibre usi... more The authors have demonstrated I .7Ghitls transmission over I65 km of dispersion-shifted fibre using a spectrum-sliced fibre amplifier light source. To the authors' knowledge, this represents the largest bit-rate distance product (ZBOGbit/s-krn) ever demonstrated using an incoherent light source. The dispersion penalty was very small (-0.3dB) even at a wavelength lOnm away from the dispersion-zero wavelength of the fibre. Introduction: There have been some attempts to provide inexpensive light sources for wavelength-division multiplexed (WDM) systems using the 'spectrum-slicing' technique. For example, the broadband light from light-emitting diodes (LEDs) or superluminescent diodes (SLDs) was spectrum-sliced by using grating-based demultiplexers and was used in WDM systems [I, 21. However, the transmission rates were limited to 2-150MbiUs over distances less than 7km because of the insufficient power available with LEDs. Thus, these light sources were mostly aimed at local-loop applications. Recently, it has been shown that the transmission distance could be extended to ll0km at l4OMhitk using an erbium-doped fibre amplifier (EDFA) [3]. Recently, we proposed a spectrum-sliced fibre amplifier light source for multichannel WDM systems [4]. The high-power amplified spontaneous emission (ASE) from an EDFA, which is already in singlemode fibre, could be efficiently divided into many channels using integrated optic WDM demultiplexers [5]. Thus, this spectrumsliced ASE could be used as a light source in a WDM system in place of several wavelength-selected DFB lasers. To demonstrate the principle, we showed that the spectrumsliced ASE source with a narrow handpass filter (-lnm) could be used for the transmission of 1.7GhiUs data. Unlike the spectrum-sliced sources based on LEDs, the application of these light sources is not necessarily limited to local-loop networks because of the strong ASE (in excess of tens of milliwatts) available from an EDFA. In addition, the chromatic dispersion would be a lesser problem for these light sources than conventional broadband sources such as LEDs because of their relatively narrow optical bandwidth. In this Letter, we demonstrate the feasibility of using these light sources in long-distance transmission systems. We performed transmission experiments at 1.7Gbit's over 165km of dispersion-shifted fibre. To our knowledge, this represents the largest bit-rate distance product (280.5Gbit/s.km) ever demonstrated

Optical path and crosstalk monitoring technique using pilot tones in all-optical WDM transport network

ABSTRACT

Phasor and OSNR monitor for DPSK/DQPSK signals based on single delay-interferometer using a 3x3 optical coupler (invited paper)

Dispersion managed fiber optic cable

High-speed fiberoptic transmission expreiment system (invited)

Recent progress on WDM PON technologies (Invited)

Optical Network Design and Modelling, 2010

Impact of using multi-level modulation format in multi-core fiber

We evaluate the impact of using high-order formats on the capacity of multi-core fiber. The resul... more We evaluate the impact of using high-order formats on the capacity of multi-core fiber. The results show that the use of higher-order format can reduce the achievable capacity per area due to its lower crosstalk tolerance.

Digital non-coherent receivers for advanced modulation formats (invited paper)

We discuss the digital signal-processing techniques for phase-adjustment-free operation of a non-... more We discuss the digital signal-processing techniques for phase-adjustment-free operation of a non-coherent receiver with the enhanced receiver sensitivity. The detection of multi-level DPSK and 16ADPSK signals is demonstrated with near quantum-limited sensitivity.

320 Gb/s (32 x 10 Gb/s) WDM transmission with 50 GHz channel spacing over 430 km of densely dispersion-managed fiber

A simple OSNR monitoring technique based on RF spectrum analysis for PDM-QPSK signals

We demonstrate a simple technique to monitor the inband OSNR of the QPSK signal by analyzing the ... more We demonstrate a simple technique to monitor the inband OSNR of the QPSK signal by analyzing the RF spectrum of the receiver noises. This technique is also applicable to the PDM-QPSK signals.

Transmission of 28-Gb/s duobinary signals over 45-km SSMF Using 1.55-µm directly modulated laser

We demonstrate the transmission of 28-Gb/s 3-level electrical duobinary signals generated by a di... more We demonstrate the transmission of 28-Gb/s 3-level electrical duobinary signals generated by a directly modulated laser over 45-km SSMF. The duobinary signals driving the laser are obtained by either a low-pass filter or delay-and-add circuit.

Electronic phase equalization technique for 10-Gb/s RSOA-based coherent WDM PON

ABSTRACT We develop an electronic phase equalization technique for the phase-modulated signal gen... more ABSTRACT We develop an electronic phase equalization technique for the phase-modulated signal generated by using the bandwidth-limited RSOA. The effectiveness of this technique is demonstrated in the 10-Gb/s, 80-km-reach WDM PON implemented by using directly-modulated TO-can packaged RSOAs and digital coherent receivers.

We report on the performance of the OSNR monitor based on the polarization-nulling technique. The... more We report on the performance of the OSNR monitor based on the polarization-nulling technique. The results show that this monitor is robust to the PMD and in-band crosstalk. For demonstration, we monitored OSNR of the optical signal transmitted through a 120-km long aerial fiber link for one week, and confirmed that OSNR could be measured with accuracy better than ±0.3 dB.