Pulsed-laser detection with pulse stretcher and noise averaging
US5206500A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1992 |
| Grant date | Apr 27, 1993 |
| Priority date | — |
| Expiry date | May 28, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/495
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photodetector receives an optical signal and converts it an electrical signal. A pulse stretcher converts the electrical signal into a first signal which is characterized by having an increased pulse width relative to the electrical signal. A noise averager converts the electrical signal into a second signal which is representative of the average noise component of the electrical signal. A threshold reference is generated as a linear function of the potential difference between the first signal and the second signal. A first comparator compares the magnitude of the first signal and the threshold reference signal and generates a first logic output which is true if the magnitude of the first signal is greater than the magnitude of the threshold reference signal. A second comparator compares the magnitude of electrical signal and the threshold reference signal and generates a second logic output which is true if the pulse width of the electrical signal measured as a funtion of time is greater than the response time of the second comparator. A logic circuit generates an alert indication if the first logic output is true and the second logic output is false.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.