Photodiode optical power monitor
AssigneeJDS Uniphase Corporation
InventorSteven J. Baumgartner
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Abstract
The invention relates to an optical power monitoring device for a photodiode assembly, which converts the DC component of a photodiode's bias current into a common mode voltage indicative of the average optical power of the incident light. The photodiode assembly, which is mountable in a conventional four-lead TO can package, includes a photodiode, a pre-amplifier, and a common mode voltage controller. The common mode voltage is added to the differential voltage, and the combined signal is output via the two data signal leads of the TO can package.
Claims13
A photodiode assembly mountable in a transistor outline can package, of the type including four leads extending therefrom, comprising:
- a photodiode for converting incident light into a photodiode current comprising an AC component indicative of an amplitude of the optical power of the incident light, and a DC component indicative of an average optical power of the incident light;
- a pre-amplifier for converting the AC component into a differential signal defined by a difference between a first alternating output signal and a second alternating output signal, complementary to the first alternating output signal;
- and
- a common-mode controller for controlling a common mode signal between the first and second alternating output signals based on the DC component;
- wherein the common mode signal and the differential output signal are combined for transmission via two of the four leads, whereby the common mode signal can be extracted from the differential output signal to provide an indication of the optical power of the incident light.
Dependencies are inferred from the claim text.