Research output: Contribution to Journal/Magazine › Journal article › peer-review
Article number | 011107 |
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<mark>Journal publication date</mark> | 6/07/2015 |
<mark>Journal</mark> | Applied Physics Letters |
Issue number | 1 |
Volume | 107 |
Number of pages | 5 |
Publication Status | Published |
<mark>Original language</mark> | English |
A terahertz (THz) imaging scheme based on the effect of self-mixing in a 2.9 THz quantum cascade (QC) amplifier has been demonstrated. By coupling an antireflective-coated silicon lens to the facet of a QC laser, with no external optical feedback, the laser mirror losses are enhanced to fully suppress lasing action, creating a THz QC amplifier. The addition of reflection from an external target to the amplifier creates enough optical feedback to initiate lasing action and the resulting emission enhances photon-assisted transport, which in turn reduces the voltage across the device. At the peak gain point, the maximum photon density coupled back leads to a prominent self-mixing effect in the QC amplifier, leading to a high sensitivity, with a signal to noise ratio up to 55 dB, along with a fast data acquisition speed of 20000 points per second.