Industrial Technology Research Institute

Dar-Zu Hsu

San-Liang Lee

Chun-Liang Yang

Jian-Ting Hong

Yu-Min Lin

Sien Chi

Chien-Hung Yeh

Hsing-Yu Chen

Yun-Lung Chou

Jye-Hong Chen

Ming-Hsiao Yang

Chia-Chien Wei

Hung-Lin Chen

Pei-Min Gong

Pei-Miin Gong

A method for receiving optical signals and a device using the same method are provided herein. The method includes the elements of receiving an input signal which includes a signal component and an interference component, wherein the interference component is subcarrier to subcarrier intermixing interference (SSII). The input signal is first converted into a frequency domain signal. The interference component of the input signal is estimated based on a mathematical model according to at least a dynamic chirp component and a static chirp component. The interference component is then cancelled from the input signal to obtain an output signal.

Method and device for receiving optical signals

A device capable of equalizing optical powers of optical signals in a passive optical network, the device comprising a first optical coupler for receiving optical signals having different optical power levels, an optical circulator capable of directing the optical signals from the first optical circulator, a laser diode capable of generating equalized optical signals having a predetermined range of optical power levels in response to the optical signals directed from the optical circulator, and a second optical coupler for receiving the equalized optical signals.

Optical power equalizer for passive optical network

An optical switch including a first reversible optical circulator and a second reversible optical circulator is provided. Each of the first reversible optical circulator and the second reversible optical circulator respectively has four I/O ports, wherein the four I/O ports are respectively a first terminal, a second terminal, a third terminal, and a fourth terminal, the four terminals sequentially transmit an optical signal in a forward circulation or a backward circulation according to a control signal, and an open end is formed between the first terminal and the adjacent fourth terminal. The open ends of the first reversible optical circulator and the second reversible optical circulator are coupled with each other.

Optical switch and optical signal communication system

A method for receiving an optical orthogonal frequency-division multiplexing (OFDM) signal and a receiver thereof are applicable to an optical OFDM system. The receiving method includes the following steps. An optical signal is converted into a digital signal. A symbol boundary of the digital signal is estimated. A guard interval of the digital signal is removed according to the symbol boundary, so as to generate an electrical signal. The electrical signal is converted into a plurality of frequency domain sub-carriers in a fast Fourier transform (FFT) manner. A timing offset is estimated with pilot carriers and frequency domain sub-carriers corresponding to the same symbol period. The estimated symbol boundary is compensated with the timing offset. Each frequency domain sub-carrier includes a plurality of pilot carrier signals. Through the receiving method, the timing offset arisen from chromatic dispersion of an optical fiber is effectively estimated and adopted for compensation.

Method for receiving optical orthogonal frequency-division multiplexing signal and receiver thereof

An optical network device of a passive optical network is introduced. The optical network device includes a light source, a control unit, and a variable optical attenuator. The light source can generate an optical signal. The control unit can generate a magnetic signal based on a control signal capable of providing information relating to a distance between the optical network device and an optical line termination. The variable optical attenuator can adjust a polarization angle of the optical signal based on the magnetic signal.

Systems and methods for interference prediction

A reconfigurable optical amplifier including a first reversible optical circulator and an optical gain device is provided. The first reversible optical circulator has four I/O ports which are respectively referred to as a first terminal, a second terminal, a third terminal, and a fourth terminal. The four I/O ports sequentially transmit an optical signal in a transmission direction of a forward circulation or a backward circulation according to a control signal. The first terminal is isolated from the adjacent fourth terminal. The optical gain device is connected between the first terminal and the adjacent fourth terminal. The second terminal and the third terminal are respectively connected to a first communication node and a second communication node.

Reconfigurable optical amplifier, reversible optical circulator, and optical signal transmission system

A non-sampling-based Q-factor measuring apparatus and method use a power conversion module to transform the power variation of inputted optical signals in time domain into the variation in other domains, such as optical wavelength, optical polarization and different output ports of optical elements. Taking optical wavelength as an example, different levels of power variation respond different outputs of wavelength variation through the use of a power-to-wavelength conversion module. An optical filter then separates the inputted optical signals with different wavelengths. The power average of a wavelength for its corresponding optical signals is further calculated by a photo detector. Thereby, the information of the power variation for the inputted optical signals at levels 1 and 0 can be obtained, and the Q-factor for the inputted optical signals is easily measured.

Apparatus and method of non-sampling-based Q-factor measuring

A non-sampling-based Q-factor measuring apparatus and method use a power conversion module to transform the power variation of inputted optical signals in time domain into the variation in other domains, such as optical wavelength, optical polarization and different output ports of optical elements. Taking optical wavelength as an example, different levels of power variation respond different outputs of wavelength variation through the use of a power-to-wavelength conversion module. An optical filter then separates the inputted optical signals with different wavelengths. The power average of a wavelength for its corresponding optical signals is further calculated by a photo detector. Thereby, the information of the power variation for the inputted optical signals at levelsandcan be obtained, and the Q-factor for the inputted optical signals is easily measured.

An apparatus and method for measuring a coherence sampling quality-factor (Q-factor) are provided, which are used to monitor quality of an optical signal in an optical network in real time. The quality is evaluated by a Q-factor. A laser diode and a wavelength converter are used in the apparatus to achieve wavelength coherence and amplification of the optical signal. Furthermore, the laser diode and an optical switch are used together to obtain an optical pulse that can be utilized to sample the optical signal. Therefore, after entering into an optoelectronic converter, a baseband signal in the optical signal is reconstructed through the amplification of the optical signal and the coupling of the optical pulse, so as to detect the Q-factor and to monitor the quality of the optical signal.

Apparatus and method for measuring coherence sampling quality-factor

A photonic label switching architecture. The architecture includes a photonic label extractor to split an externally input first optical packet data into a photonic label and a payload. Then, the photonic label is input to a photonic label processing and swapping device to duplicate as a plurality of parallel copies for decoding and producing an auto-correlation output. According to the auto-correlation output, a photonic label swapping path is chosen, a new photonic label is produced, and an output port of an optical switch is chosen. A new optical packet data which is the result of the new photonic label adjoining the payload is output to the chosen output port of the optical switch.

Photonic label switching architecture

An apparatus and a method for monitoring optical signal-to-noise ratio are provided. It can be applied in dense wavelength-division multiplexed networks to monitor the transmission quality of each optical channel. The apparatus comprises an optical circulator, a tunable optical filter, a dithering signal, a dithered reflector, and two photodiodes. It can be integrated on a single chip. The invention utilizes the dithering and reflection functions of the dithered reflector, and passes the signal and the noise through the tunable optical filter once and twice, respectively. When the tunable optical filter is scanning and filtering the whole spectrum, the signal and noise powers are measured by the two photodiodes, respectively. The OSNR for each optical channel is then calculated according to the signal and noise powers. It can monitor channel location, wavelength drift, and OSNR by including a wavelength locker to act as an optical channel analyzer.

Apparatus and method for monitoring optical signal-to-noise ratio

The present invention provides a wavelength converter with wideband four-wave-mixing, which includes a laser diode, an optical modulator, a first and a second polarization controllers, a first, a second and a third tunable lasers, an optical coupler, a semiconductor optical amplifier (SOA) and a multiplexer. The present invention utilizes an assist beam that can improve the recovery rate and saturation power of the SOA. While the SOA is operated at a bias current close to the transparent condition for the assist beam, it does not influence the gain of the SOA wavelength converter.

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Tainan County, Taiwan

Dar-Zu Hsu