• ETRI Journal
• /
• v.35 no.1
• /
• pp.1-6
• /
• 2013

In this paper, we present an implemented serial 40-Gb/s receiver optical subassembly (ROSA) module by employing a proposed TO-CAN package and flexible printed circuit board (FPCB). The TO-CAN package employs an L-shaped metal support to provide a straight line signal path between the TO-CAN package and the FPCB. In addition, the FPCB incorporates a signal line with an open stub to alleviate signal distortion owing to an impedance mismatch generated from the soldering pad attached to the main circuit board. The receiver sensitivity of the ROSA module measures below -9 dBm for 40 Gb/s at an extinction ratio of 7 dB and a bit error rate of $10^{-12}$.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.1
• /
• pp.108-111
• /
• 2016

We propose the method for measuring sensitivity of optical receiver of a long-range laser range finder in real-time. The sensitivity of the detector can be calculated using the detected voltage of the reference sensor, the area of the reference sensor and the transmittance ratio of neutral density filters. To evaluate the performance of the proposed method, we implemented a system and performed experiments. As a result, this system can be measured from 2nW to $113{\mu}W$. With this system, we measured the sensitivity of 37nW and 7nW with PIN PD and APD sample, respectively. This system has the advantage for the performance test of an optical sensor module in the long-range laser range finder.

• Proceedings of the Optical Society of Korea Conference
• /
• 2004.02a
• /
• pp.284-285
• /
• 2004

We have developed a 10 Gbps receiver consist of an InGaAs PIN PD and an embedded TIA(transimpedance preamplifier). The receiver is assembled in a small form factor (SFF) Package. It shows f-3dB of 10 GHz and the sensitivity more than -20 dBm at 10$^{-10}$ BER (bit-error-rate) for 10 Gbps optical input signal of 2$^{31}$-1 PRBS (pseudo-random-bit-sequence).

• Korean Journal of Optics and Photonics
• /
• v.19 no.5
• /
• pp.343-348
• /
• 2008

This study was carried out to commercialize FTTH by developing a burst mode optical receiver for E-PON. The optical receiver was manufactured by minimizing the capacitance of a photodiode to improve sensitivity for meeting 10, 20 km OLT Rx standard of E-PON at the transmission speed of 1.25 Gb/s. When bit-error ratio is $10^{-12}$ and PRBS is $2^5-1$, sensitivity is -26 dBm, loud/soft ratio is 23 dB. Both preamble time and guard time were set to 102.4 ns (128 bit). After comparing a photodiode whose capacitance is 0.53 pF with another photodiode whose capacitance has been minimized to 0.26 pF, we could see that sensitivity improved to 0.7 dBm and so did bandwidth to 190 MHz of burst mode for the optical receiver manufactured by the photodiode whose capacitance is 0.26 pF.

• ETRI Journal
• /
• v.28 no.1
• /
• pp.103-106
• /
• 2006

We have fabricated a planar lightwave circuit (PLC) hybrid-integrated optical sub-assembly of a triplexer using a thin film filter (TFF)-attached wavelength division multiplexer (WDM) and photodiode (PD) carriers. Two types of TFFs were attached to a diced side of a silica-terraced PLC platform, and the PD carriers with a $45^{\circ}$ mirror on which pin-PDs were bonded were assembled with the platform. A clear transmitter eye-pattern and minimum receiver sensitivity of -24.5 dBm were obtained under 1.25 Gb/s operation for digital applications, and a second-order inter-modulation distortion (IMD2) of -70 dBc was achieved for an analog receiver.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.11
• /
• pp.1113-1120
• /
• 2003

It is expected in the future that the demand of optical subcarrier multiplexing system, in which a number of small size base stations with only antenna and RF transmission are connected to central station using optical fiber, will be increased in the CDMA digital cellular mobile communication network. In this paper, in order to analysis the performance of optical SCM system fur CDMA RF signal transmission, MZ modulator is modelled as a non-linear transfer function with cubic operation. The performance degradation due to multipath signals and other user signals through MB modulator is analyzed and the performance is improved using the Rake receiver.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.10
• /
• pp.1940-1946
• /
• 2015

An optical coherent system is considered for the next-generation optical access networks in enhancing the data rate and transmission distance. In this system, however, I/Q amplitude imbalance may occur at several parts of the system, leading to serious performance degradation. Asymmetric structure of a coherent receiver at the location of subscriber is one of the sources of I/Q imbalance. Therefore, this imbalance parameters must be removed or compensated to secure the transmission performance. In this paper, the source of I/Q amplitude imbalance is analyzed, and then the way to compensate for the imbalance at the receiver side is suggested. Performance after the compensation is estimated using simulation.

• Journal of the Optical Society of Korea
• /
• v.2 no.1
• /
• pp.22-25
• /
• 1998

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 $1{\imes}10^{-10}$ BER.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.2
• /
• pp.25-31
• /
• 2020

In an optical system that serves as the backbone of an information transmission system, it is essential to evaluate the statistical characteristics of the signal and noise for a performance evaluation and optimization of the system. The optical receiver system improves the reception sensitivity by adopting an optical amplifier in front of the optical detector to improve the reception sensitivity, but some problems change the bandwidth of the electronic signal to the optical signal in the optical receiver due to the ASE noise added to the output of the optical detector. The problem of changing the ratio of the bandwidth of these signals varies according to the passband characteristics of the filter present at the output stage. The frequency response effect can be solved by constructing an infinite order filter, but it is almost impossible to implement it. In this paper, the Butterworth filter was implemented to evaluate the frequency response characteristics of an optical receiver system according to the filter order. The simulation results showed that the receiver sensitivity increases as the order of Butter-Worth filters increases. In addition, as a result of simulation of the change of various values, it was confirmed that the reception sensitivity increased with increasing. That is, the average photocurrent increases, and the dispersion decreases with increasing.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.1
• /
• pp.677-682
• /
• 2015

In this paper, we investigated the effect of light on the performance of the receiver system noise and external noise added from the ever-present influence in general optical system. And calculated the reception sensitivity of the receiver at the time of off-keying transmission - from the optical transmission system in consideration of the case that the photo detector has a quantum yield of less than one-one. Not less than 50 it was confirmed that it is possible to configure the low power system is calculated and compared with the case where less than 300 the receiver sensitivity of the optical system to maintain the standard error probability. However, even if these values were considered, and the preamplifier in the receiver, considering a case of using a low-output light source, so that a heavy burden in the value less than the actual system installation, using the light source having less than the output, as shown in Figure 3, the results that were obtained also may be used.