The present invention is directed to communication systems and techniques thereof. More specifically, embodiments of the present invention provide a calibration system for optical transmitter. The calibration system provides a predetermined set of operating parameters to the optical transmitter and measures the second harmonic value of the transmitter output. A calibrated set of parameters is determined by selecting operating parameters associated with the minimum second harmonic value. There are other embodiments as well.

Embodiments of the invention include a phase adjustor for adjusting a phase angle of a local oscillator relative to a phase angle of a signal input of a Device Under Test (DUT). Some embodiments include a laser source for a lightwave component analyzer and an optical phase adjustor. The lightwave component analyzer drives a first test input to the DUT. An output of the DUT drives an output of the optical phase adjustor adapted to couple to an oscillator input to the DUT. A monitor selector is also included that accepts at least two outputs of the DUT and is structured to transmit a selected output of the DUT to the phase adjust driver. The phase adjust driver is structured to drive the optical phase adjustor with a control signal based on the output of the DUT that is selected by the monitor selector.

A single-ended data transmission system transmits a signal having a signal voltage that is referenced to a power supply voltage and that swings above and below the power supply voltage. The power supply voltage is coupled to a power supply rail that also serves as a signal return path. The signal voltage is derived from two signal supply voltages generated by a pair of charge pumps that draw substantially same amount of current from a power supply.

Techniques are described for determining, with a first optical node, a correction factor indicative of an amount of optical power loss that a Raman amplifier in a second optical node causes in an optical signal having a first wavelength that is transmitted by the first optical node and received by the second optical node, transmitting, with the first optical node to the second optical node, information, based on the determined correction factor, that is to be used for determining a gain of the Raman amplifier, and transmitting, with the first optical node to the second optical node, an optical signal having a second wavelength that is to be amplified by the Raman amplifier.

An inspecting device has an optical switch selectively coupling a light source unit with each of light input/output ports; a first light detecting unit detecting a first intensity of test light input from an inspecting device on a counterpart side and passing through the optical switch; a second light detecting unit detecting a second intensity of the test light directed from the light source unit toward the optical switch; a third light detecting unit optically coupled to another end of a test optical fiber having one end connected to each of the plurality of light input/output ports, and detecting a third intensity of the test light received from the light source unit via the test optical fiber; and an internal loss recording unit recording a loss of an optical path inside the device obtained on a basis of a difference between the third intensity and the second intensity.

Embodiments described herein may be related to apparatuses, processes, and techniques related to active optical plugs used to cover optical connectors of a photonics package to protect the connectors. The active optical plugs may also be used to perform testing of the photonics package, including generating light to be sent to the photonics package and to detect light received from the photonics package as part of the test protocol. This allows testing the optical connection and the photonics package, without exposing the optical connections of the package to damage from dust or physical contact. Other embodiments may be described and/or claimed.

Architectures and techniques are presented that improve or enhance a network planning procedure such as by selecting a more efficient test buffer that is used to identify objects that might intersect a Fresnel zone between two transceivers. An improved test buffer (e.g., buffer region) can be one that is constructed from a plurality of rectangles situated along a line of sight of the two transceivers and that are oriented according to cardinal directions.

Systems and methods for avoiding fiber damage of an optical fiber link are provided. A method, according to one implementation, includes monitoring optical signals transmitted along an optical fiber link from an output port of a first card to an input port of a second card. In response to detecting a fiber disconnection state when an amplifier of the first card is operating in a normal condition, the amplifier of the first card enters a forced Automatic Power Reduction (APR) condition. In addition to potentially reducing the risk of eye damage from laser light emitted from the optical fiber link, the forced APR condition is configured to allow for an uninterrupted debugging procedure. Also, the method includes returning the amplifier of the first card from the forced APR condition back to the normal operating condition after receiving an indication that the fiber disconnection state has cleared.

A light source (12) outputs a light (L1). A branching unit (13) branches the light (L1) output from the light source (12) into a first branched light (L2) and a local oscillation light (LO). A modulator (14) modulates the first branched light (L2) to output an optical signal (LS1). A receiver (15) causes the local oscillation light (LO) to interfere with an optical signal (LS2) to receive the optical signal (LS2). An EDFA (16) amplifies the optical signal (LS1) output from the modulator (14). An excitation light source (17) outputs an excitation light (Le) exciting the EDFA (16) to the EDFA (16). An optical attenuator (18) attenuates optical power of the optical signal (LS1) amplified by the EDFA (16). A control unit (11) controls attenuation of the optical signal (LS1) in the optical attenuator (18). The control unit (11) adjusts the attenuation of the optical signal (LS1) and adjusts an output of the excitation light (Le) from the excitation light source (17).

An extinction ratio testing system (10) includes a microcontroller (102), an extinction ratio tester (104), and a thermostat (106). The microcontroller (102) controls the thermostat (106) to maintain an optical transceiver module (20) at a predetermined high temperature, and then the microcontroller (102) controls the extinction ratio tester (104) to test an extinction ratio of the optical transceiver module (20). If the extinction ratio is lower than a standard extinction ratio, the microcontroller (102) controls the optical transceiver module (20) to increase a laser operating current (212) of the optical transceiver module (20) to increase the extinction ratio.