Patent · US Expired

Radiation characteristic measuring apparatus for laser diode

US4798950A · kind A · utility

2Cited by
2References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 4, 1986
Grant dateJan 17, 1989
Priority date
Expiry dateSep 4, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01J1/4257
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An apparatus for measuring a radiation characteristic of a laser diode. An AC signal and a step-like DC voltage are applied to the laser diode and the radiant power output thereof is received by a photodiode having an output to which a first amplifier, a transformer, a capacitor and an AC amplifier for extracting the AC signal. The apparatus further comprises a first switch connected between the input of the first amplifier and the capacitor, and a second switch connected between both ends of the transformer. Every time the step-like voltage is stepped up, the first and second switches are closed for a short time as compared with the duration of a step period to protect the measurement from the influence of the change in the DC voltage.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.