A composite connector for optical power meter is provided, which includes a fixation base and an active connection base. The fixation base is installed on an optical power meter; the fixation base includes a left hole, a right hole and a central hole. The active connection base includes a bottom plate, an active pin, a first fiber socket and a second fiber socket. The first fiber socket and the second fiber socket are disposed on the bottom plate. The active pin penetrates through the bottom plate and is inserted into the left hole, whereby a first circle, whose center is at the active pin and circumference passes through the first fiber socket as well as the second fiber socket, overlaps a second circle, whose center is at the left hole and circumference passes through the central hole, in the normal direction of the active connection base.

A method includes defining a Center-of-Radiation Reference for a device under test, the CORR indicating a reference origin of an electromagnetic wave pattern formable with the DUT; determining a 3-dimensional orientation information with respect to the CORR, the 3-dimensional orientation information indicating a direction of the electromagnetic wave pattern; and providing the CORR and the 3-dimensional orientation information to a measurement system.

A method includes defining a Center-of-Radiation Reference for a device under test, the CORR indicating a reference origin of an electromagnetic wave pattern formable with the DUT; determining a 3-dimensional orientation information with respect to the CORR, the 3-dimensional orientation information indicating a direction of the electromagnetic wave pattern; and providing the CORR and the 3-dimensional orientation information to a measurement system.

An optical end monitoring apparatus in an optical communication network includes an optical transmitting unit, an optical receiving unit, and a decision unit. The optical transmitting unit generates first and second optical signals with different wavelengths and transmits the first and second optical signals to the optical end terminal over an optical cable. The optical receiving unit receives reflection signals corresponding to the respective first and second optical signals. The decision unit determines whether the optical end terminal is connected to the optical cable using a difference between magnitudes of the respective received reflection signals.

A test apparatus has at least one optical source, a high-speed photodetector, a microcontroller or processor, and electrical circuitry to power and drive the at least one optical source, photodetector, and microcontroller or processor and for measuring the frequency response of a multimode optical fiber under test. The test apparatus can utilize an optical pulse waveform with a light adapter to measure of the channel under test. It can also uses a correction method to de-embeed a chromatic bandwidth of the source from the encircled flux modal chromatic bandwidth. The correction method can use correction functions obtained for different type of VCSELs to estimate the optical channel bandwidth when used with VCSEL transceivers.

A method for setting a pluggable optical transceiver, includes: amplifying, with an amplifier, an electrical signal being input to the pluggable optical transceiver from an external device to which the pluggable optical transceiver is mounted, and outputting the amplified electrical signal as a drive signal of an optical modulator; modulating light input from a light source with the optical modulator, based on the drive signal, and outputting the modulated light; monitoring amplitude of the drive signal; and executing a control sequence being set in advance for at least one of the amplifier and the optical modulator when detecting that amplitude of the drive signal exceeds a reference value being set in advance.

A method for setting a pluggable optical transceiver, includes: amplifying, with an amplifier, an electrical signal being input to the pluggable optical transceiver from an external device to which the pluggable optical transceiver is mounted, and outputting the amplified electrical signal as a drive signal of an optical modulator; modulating light input from a light source with the optical modulator, based on the drive signal, and outputting the modulated light; monitoring amplitude of the drive signal; and executing a control sequence being set in advance for at least one of the amplifier and the optical modulator when detecting that amplitude of the drive signal exceeds a reference value being set in advance.

Optical signal to noise ratio within a band of interest (in-band OSNR) is calculated by using a reference signal for noise estimation. In-band noise at a node along the optical communication path is estimated by subtracting the reference signal contribution from the received in-band signal energy. Contribution from the reference signal is calculated using an effective transfer function of the optical communication path using either a direct method in which measurements are made a priori on an equivalent optical system or an indirect method in which the effective transfer function is calculated using computerized simulations. The selection of which method to use may be based on the desired resolution bandwidth for the estimation of transfer function.

Optical signal to noise ratio within a band of interest (in-band OSNR) is calculated by using a reference signal for noise estimation. In-band noise at a node along the optical communication path is estimated by subtracting the reference signal contribution from the received in-band signal energy. Contribution from the reference signal is calculated using an effective transfer function of the optical communication path using either a direct method in which measurements are made a priori on an equivalent optical system or an indirect method in which the effective transfer function is calculated using computerized simulations. The selection of which method to use may be based on the desired resolution bandwidth for the estimation of transfer function.

Systems and methods for measuring the in-phase/quadrature (I/Q) skew of optical signals are disclosed. The method may be used to characterize the I/Q skew of optical signals transmitted by optical coherent transponders in complex modulation formats. The method may include providing an input signal to a transponder to produce a periodic (and generally sinusoidal) output signal, providing the output signal to a test system including an optical spectrum analyzer, measuring the optical power of a first harmonic of the signal, and comparing the measured optical power to calibration data to determine the I/Q skew. The optical power may be analyzed in a portion of the spectrum where sensitivity of the power to changes in skew is highest. The calibration data may map previously-obtained optical power measurements to corresponding known skew amounts. The system may provide more accurate skew measurements using less expensive equipment than existing skew measurement methods.