Ja-Won Seo

AC-coupled burst-mode OLT SFP transceiver for gigabit ethernet PON systems

This letter presents a burst-mode optical line terminal transceiver for a gigabit ethernet passive optical network system. The transceiver package is compliant with small form-factor pluggable multisource agreement. The burst-mode receiver employs an ac-coupling between commercial transimpedance amplifier and limiting amplifier. The burst-mode receiver achieves sensitivity of -24.4 dBm at bit-error ratio 10/sup -12/ with pseudorandom bit sequence 2/sup 7/-1 data, overload of -1.5 dBm, and system dynamic range of 22.9 dB for preamble of 512 bits and guard time of 32 bits. Burst-mode penalty of 1.6 dB is also observed by experiment.

Contrast enhancement of back-light images via a regional rank-1 constraint

In this paper, we propose a novel approach for enhancing the contrast of back-light images. Although many contrast enhancement methods have been proposed in the literatures, they are still prone to fail especially in restoring the textural details of the under-exposed regions in back-light images. To cope with this problem, the proposed approach employs a new pixel-wise gain correction scheme that adopts a regional rank-1 constraint. Based on this scheme, the contrast of the back-light image is enhanced notably while allowing smooth intensity changes and suppressing intensity inversions around adjacent pixels. In the experiments, the effectiveness of the proposed method is demonstrated qualitatively and quantitatively comparing with the state-of-the-art methods.

Embodiment of optical interconnection circuits for the mobile phone application

This paper intends to show that the optical interconnection can be a substitute of the electrical serial interface in mobile application. We designed the optical interconnection interface circuits on the evaluation boards which typically correspond to the mobile phone and transferred the data through the optical waveguide module. There are 4 pairs of VCSEL (Vertical Cavity Surface Emitting Laser) and PD (Photo Diode) arrays in the waveguide module and they are used to send the strobe and the data signal in dual-simplex (i.e. Two Directions with Unidirectional Lanes) configuration. We have demonstrated a successful data transmission of moving picture and real-time camera module images to the main-LCD (Liquid Crystal Display) repeatedly and the still pictures to the sub-LCD at the maximum speed of 400Mbps.