Abstract: The present invention relates to an optical coupling/splitting device that realizes the splitting of a down-signal and the coupling of up-signals by the same optical device, and reduces coupling losses of the up-signal. An optical coupling/splitting device in the present invention comprises an optical coupling/splitting means for coupling a plurality of up-signals in a multi-mode for output and splitting a down-signal in a single mode for output, and a two-way optical propagation means for propagating the up-signal that is output from the optical coupling/splitting means in a multi-mode for output and propagate the down-signal in a single mode to be output to the optical coupling/splitting means.

Abstract: A self-diagnostic method for PON protection system, in which optical switch-related failure can be previously inspected, and a PON protection system.

Abstract: A normal system OSU, a redundancy system OSU, an optical switch, a concentration switch, and a controller which detects a command input by operation control and performs control according to the command are provided, and in such a state that the controller detects a redundancy system switching command indicating that the normal system OSU is switched to the redundancy system OSU, the controller induces the concentration switch to change a storage destination of a down signal, instructs the normal system OSU which is the switching source OSU to stop transmission of a transmission permission message, instructs the optical switch to switch a path after receiving remaining data processing completion notifications from the concentration switch and the normal system OSU which is the switching source OSU, writes accumulated information about the normal system OSU, which is the switching source OSU, in the redundancy system OSU, and notifies the concentration switch of completion of switching, whereby a down signal i

Abstract: A self-diagnostic method for PON protection system, in which optical switch-related failure can be previously inspected, and a PON protection system.

Abstract: A normal system OSU, a redundancy system OSU, an optical switch, a concentration switch, and a controller which detects a command input by operation control and performs control according to the command are provided, and in such a state that the controller detects a redundancy system switching command indicating that the normal system OSU is switched to the redundancy system OSU, the controller induces the concentration switch to change a storage destination of a down signal, instructs the normal system OSU which is the switching source OSU to stop transmission of a transmission permission message, instructs the optical switch to switch a path after receiving remaining data processing completion notifications from the concentration switch and the normal system OSU which is the switching source OSU, writes accumulated information about the normal system OSU, which is the switching source OSU, in the redundancy system OSU, and notifies the concentration switch of completion of switching, whereby a down signal i

Abstract: The present invention relates to an optical coupling/splitting device that realizes the splitting of a down-signal and the coupling of up-signals by the same optical device, and reduces coupling losses of the up-signal. An optical coupling/splitting device in the present invention comprises an optical coupling/splitting means for coupling a plurality of up-signals in a multi-mode for output and splitting a down-signal in a single mode for output, and a two-way optical propagation means for propagating the up-signal that is output from the optical coupling/splitting means in a multi-mode for output and propagate the down-signal in a single mode to be output to the optical coupling/splitting means.

Abstract: In the present invention, the extremely complicated setting and control and an extremely expensive optical component (wavelength locker) are not required, and optical output wavelength and optical output power can simply be set and controlled at a moderate price. At least one value for determining a dependence of the optical output wavelength on drive current and device temperature and at least one value for determining a dependence of the optical output power on drive current and device temperature in a light emitting device constituting first means 1 for emitting light are stored in fourth means 4.

Abstract: In the present invention, the extremely complicated setting and control and an extremely expensive optical component (wavelength locker) are not required, and optical output wavelength and optical output power can simply be set and controlled at a moderate price. At least one value for determining a dependence of the optical output wavelength on drive current and device temperature and at least one value for determining a dependence of the optical output power on drive current and device temperature in a light emitting device constituting first means 1 for emitting light are stored in fourth means 4.

Abstract: The present invention provides wavelength monitoring and/or control enabling size reduction and low power operation without requiring a complicated optical system in its wavelength monitoring and controlling mechanism. The measurement portion (1) measures temperature by a thermistor (5) in the measurement portion, and measures a bias current by using an LD drive current detecting circuit (6). The LD temperature, optical output and bias current are measured by the measurement portion. The relationship between the LD temperature and wavelengths or between the temperature, bias current and wavelengths is stored in a memory map of the storage portion (2). The central controlling portion (3) calculates wavelengths on the basis of the temperature and the bias current or the temperature information of the measurement portion, and the relationship between the LD temperature, bias current and wavelengths or between the temperature and wavelengths of the storage portion.

Abstract: The present invention provides wavelength monitoring and/or control enabling size reduction and low power operation without requiring a complicated optical system in its wavelength monitoring and controlling mechanism. The measurement portion (1) measures temperature by a thermistor (5) in the measurement portion, and measures a bias current by using an LD drive current detecting circuit (6). The LD temperature, optical output and bias current are measured by the measurement portion. The relationship between the LD temperature and wavelengths or between the temperature, bias current and wavelengths is stored in a memory map of the storage portion (2). The central controlling portion (3) calculates wavelengths on the basis of the temperature and the bias current or the temperature information of the measurement portion, and the relationship between the LD temperature, bias current and wavelengths or between the temperature and wavelengths of the storage portion.