Light receiving circuit for use in electro-optic sampling oscilloscope
US6384590B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 10, 1999 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Nov 10, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R13/347
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a light receiving circuit for use in electro-optic sampling oscilloscope which receives first and second optical, photodiodes 51 and 52 are connected in series between a positive bias power supply 50P and a negative bias power supply 50N. The photodiodes 51 and 52 receive optical signals whose polarization state correspond to the voltage of a signal to be measured and convert the thus-received optical signals into electric signals. An amplifier 53 amplifies an electric current appearing in a point of connection P between the photodiodes 51 and 52. A current monitor 54 detects the electric signal converted by the photodiode 51, and a current monitor 57 detects the electric signal converted by the photodiode 52. The electric signal detected by the current monitor 54 is subjected to analog-to-digital conversion by an analog-to-digital converter 55, and the electric signal detected by the current monitor 57 is subjected to analog-to-digital conversion by an analog-to-digital converter 58. A control section formed from a subtraction circuit 60 controls a ratio of polarization between the optical signals such that the difference between the value of the current detected by the current…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.