Apparatus and method of power measurement for pulsed terahertz quantum-cascade laser
US8749225B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2011 |
| Grant date | Jun 10, 2014 |
| Priority date | — |
| Expiry date | Aug 29, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/3402
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention provides a power measurement apparatus and method for a pulsed terahertz quantum-cascade laser (THz QCL). The apparatus includes a light source part, a light path part, and a detection part. Terahertz light emitted by a THz QCL reaches a terahertz quantum-well photodetector (THz QWP) through the measurement apparatus, and is absorbed to generate a corresponding current signal. A signal processing circuit extracts a voltage signal from the current signal, amplifies the voltage signal, and inputs the amplified voltage signal to an oscilloscope for reading and displaying. According to a responsivity of the THz QWP at a lasing frequency of the laser, the measurement of the output power of the pulsed THz QCL is acquired. The present invention avoids integration estimation when a thermal detector is used to measure output power of a THz QCL in a pulse operating mode, and can directly acquire the power value of a pulsed output from the laser according to the amplitude of the detector responding to the pulsed terahertz light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.