Infinera Corporation

National Semiconductor Corporation

Smith, Robert W., Jr.

Nilsson, Alan C.

Freeman, Paul N.

Kagan, Yishai

Robert W Smith

Alan C Nilsson

Paul Nathan Freeman

Yishai Kagan

Lawrence Herbert Zuckerman

Merry Riehm-Constantino

Perry Tsao

Alexander Reding

A power monitoring and correction to a desired power level of a laser or group of lasers utilizes two photodetectors which are employed to accurately determine the amount of output power from the front end or 'customer' end of a laser or a plurality of such lasers. During power detection, which may be accomplished intermittently or continuously, the laser is modulated with a tone of low frequency modulation. One photodetector at the rear of the laser is employed to detect the DC value of the frequency tone, i.e., a value or number representative of the AC peak-to-peak swing, amplitude or modulation depth of the tone. Also, the rear photodetector may be employed to determine the optical modulation index (OMI). In either case, these values may be employed in a closed loop feedback system to adjust or otherwise calibrate the value of the low tone frequency relative to the total desired bias current applied to the laser. A front photodetector is employed to receive a portion of the total output of the laser, or of each laser, and the average output power of the laser, or of each laser, is determined from already knowing the optical modulation index (OMI) via the rear photodetector. Thus, by measuring and/or calibrating the laser OMI with the use of a rear photodetector, the average output power from the front end output can be unambiguously determined from detection of the AC peak-to-peak swing or amplitude of the low frequency tone received via the front photodetector.

Monitoring of a laser source with front and rear output photodetectors to determine frontal laser power and power changes over laser lifetime

An apparatus includes terminals configured to be coupled to a string wiring of a photovoltaic string. The apparatus also includes a power controller configured to control a power provided over the string wiring by a photovoltaic panel in the photovoltaic string. The apparatus further includes a wireless radio configured to at least one of transmit and receive wireless signals using the string wiring as an antenna. The wireless signals contain data associated with the photovoltaic panel and/or the power controller. For example, the wireless radio could be configured to receive a first signal containing a command for the power controller from the string wiring and to provide the command to the power controller. The wireless radio could also be configured to receive an acknowledgement associated with the command from the power controller and to transmit a second signal containing the acknowledgement over the string wiring for wireless transmission.

Use of photovoltaic array string wiring as antenna and transmission line for wired and wireless data communications

A transmissive active channel element is provided in each signal channel of a monolithic multi-channel TxPIC where each channel also includes a modulated source. The active channel element functions both as a power control element for both monitoring and regulating the output channel signal level of each signal channel and as a modulator for channel wavelength tagging or labeling to provide for wavelength locking the modulated sources. The power regulating function is also employed to control the channel signal power outputs of each channel to be uniform across the channel signal array. All of these functions are carried out by a feedback loop utilizing digital signal processing.

Wavelength locking and power control systems for multi-channel photonic integrated circuits (PICs)

Wavelength locking and power control systems for multi-channel photonic integrated circuits (PICS)

Growing community of inventors

Sonoma, CA, United States of America

Robert W Smith