Abstract: The present disclosure relates to a signal processing method and a bidirectional coarse wavelength division multiplexing (CWDM) ring network system allocating at least two wavelength channels per a single wavelength grid to thereby increase the numbers of wavelength channels. The bidirectional CWDM ring network system is configured to form an optical signal having specific wavelength; allocate at least two wavelength channels per a single CWDM wavelength grid; and add an optical signal having specific wavelength to the optical signal formed in at least two the optical transceivers or drop an optical signal having specific wavelength to the optical signal formed at the at least two optical transceivers.

Abstract: An AR coated quantum dot resonator implementing a wavelength independent light source to resolve a drawback of degradation in the property of a high temperature optical output due to AR coating of LED or wavelength locked light source, which is filtered to a narrow line width, is disclosed. In one embodiment, a gain medium includes at least one quantum dot and an anti-reflection (AR) coated reflection plane at one of front and rear planes of the gain medium. The gain medium has a wide line width due to different sizes and distribution of a plurality of quantum dots. The line width includes entire wavelength channels of a WDM or WDM-PON. Also, the AR coated reflection plane is a front reflection plane having a lower reflectivity (e.g., 0.001% to 1%.) than that of a rear reflection plane.

Abstract: Embodiments of a periodically filtered broadband light source are described. The periodically filtered broadband light source includes a periodic spectral filter coupled to an optical gain element to generate a light and to filter the light into a plurality of individual spectral slices. The broadband light source includes an isolator coupled to the optical gain element. The periodic filter can be a reflective filter. The periodic filter can adjust an optical power in each of the spectral slices. The periodic filter can include one or more control elements to control an optical power in each of the spectral slices. Further, a wavelength division multiplexing passive optical network system is described that includes the periodic broadband light source to send individual spectral slices to wavelength lock one or more transceivers. The individual spectral slices sent by the periodic broadband light source match wavelength channels of a wavelength division multiplexer/de-multiplexer.

Abstract: A hybrid network optical communication system is provided. The system may include a central office, at least one network group coupled to the central office. The network group may include a plurality of external rings, and each of the external rings may include a plurality of nodes having a ring connection. This system may have economical advantages of reducing the number of optical cores and easily switching directions for protecting the system when any problems occur on the optical cores and the devices at nodes.

Abstract: Embodiments of a periodically filtered broadband light source are described. The periodically filtered broadband light source includes a periodic spectral filter coupled to an optical gain element to generate a light and to filter the light into a plurality of individual spectral slices. The broadband light source includes an isolator coupled to the optical gain element. The periodic filter can be a reflective filter. The periodic filter can adjust an optical power in each of the spectral slices. The periodic filter can include one or more control elements to control an optical power in each of the spectral slices. Further, a wavelength division multiplexing passive optical network system is described that includes the periodic broadband light source to send individual spectral slices to wavelength lock one or more transceivers. The individual spectral slices sent by the periodic broadband light source match wavelength channels of a wavelength division multiplexer/de-multiplexer.

Abstract: A method to reduce optical intensity modulation is described that involves generating a spiraling wave onto an acoustic-optic interaction portion of an optical fiber within an acousto-optic filter in order to create reflected waves that are orthogonal with respect to waves that are originally launched onto the interaction portion. A transducer is described having a first section and a second section. The first and second sections each have a polling direction along a first axis. The transducer also has a third section and a fourth section. The third and fourth sections each have a polling direction along a second axis. The third and fourth sections are each between the first and second sections. An acousto-optic filter having a horn with an elliptical cross section coupled to a transducer is also described. A transducer for an excitation element capable of launching spiraling acoustic waves is described.

Abstract: An apparatus is provided in which multiple devices are connected in series forming a signal path through which a signal propagates. Each device may have one or more operating frequencies and each operating frequency may generate a corresponding intensity modulation with respect to the signal. For one embodiment, the apparatus includes multiple delay lines through which the signal travels. The length of each delay line is configured to reduce the intensity modulation generated by each device based upon one or more factors including the one or more operating frequencies associated with each device and multiple null orders corresponding to different lengths of the delay lines.