Abstract: Provided is an apparatus for connecting a wavelength division multiplexing passive optical network (WDM-PON) to a time division multiplexing passive optical network (TDM-PON). In a hybrid, passive optical network which is a combination of the WDM-PON and the TDM-PON, the apparatus is formed at a subscriber side for matching the WDM-PPN and the TDM-PON. Accordingly, a passive remote mode can be implemented as a passive node not an active node. Therefore, the entire optical network can be efficiently operated. In addition, since the apparatus located on the subscriber side uses a wavelength-tunable light source, any dependency on the wavelength of a WDM-PON optical signal is removed.

Abstract: A seed light module based on a single longitudinal mode oscillation light source is provided.

Abstract: A spectrum-sliced seed light module for a wavelength division multiplexing passive optical network (WDM PON) is provided. The seed light module includes an optical amplifier to amplify seed light, an optical wavelength filter to transmit broadband light, which is output in opposite direction to an output direction of the seed light, at periodic frequency intervals, and a reflective mirror to reflect light which is spectrum-sliced through the optical wavelength filter to the optical wavelength filter.

Abstract: Disclosed are an optical transmission apparatus and method in a wavelength division multiplexing passive optical network (WDM-PON). The optical transmission apparatus outputs an optical signal by applying a DC bias current and an RF signal to a laser diode at a threshold current level of the laser diode, thereby broadening an optical spectrum of the laser diode. Accordingly, an optical link becomes less vulnerable to reflection induced noise, which contributes to improve stability and reliability of the optical link.

Abstract: There are provided a method and system for monitoring an optical transmission line. The system for monitoring the optical transmission line includes: an OTDR (optical time-domain reflectometer) transmitting a monitoring light to an optical transmission line, measuring a reflected light or backscattered light to monitor the optical transmission line; an optical amplification unit amplifying the monitoring light transmitted on the optical transmission line by using a gain clamped optical amplifier; and a filter unit removing a component having a wavelength outside a wavelength band of the monitoring light from a backward ASE (amplified spontaneous emission) generated by the optical amplification unit. Accordingly, it is possible to extend an optical transmission line monitoring distance of the OTDR. As a result, it is possible to prevent deterioration of the performance of the OTDR because of the backward ASE.

Abstract: A long-wavelength band (L-band) optical amplifier capable of maintaining a gain constant, thereby providing a stable optical output even when an optical power or a wavelength of a signal input thereto changes. The optical amplifier includes an amplifier which amplifies an input signal, and an amplified spontaneous emission (ASE) reflector which reflects backward ASE generated by the amplifier so that the backward ASE is fed back to the amplifier.

Abstract: The present invention provides an apparatus and method for compensating for the variation of a gain spectrum attributable to the temperature variation of a fiber amplifier, and a long-wavelength band dispersion-compensating hybrid amplifier equipped with the gain spectrum compensating apparatus. The apparatus includes a DCF located between a first amplification stage and a second amplification stage to compensate for dispersion of an optical signal output from the first amplification stage and perform Raman amplification of the optical signal using input pumping light; at least one pumping light provision means for providing forward or backward pumping light to the DCF; first and second temperature detection means for detecting temperature variations of the first and second amplification stages, respectively; and control means for controlling intensity of the pumping light of the pumping light provision means according to the detected temperature variations.