Efficient trigger signal generation from wasted backward amplified stimulated emission at optical amplifiers for optical coherence tomography
1 Smart Manufacturing Technology Group, KITECH, 35-3, HongCheon, IpJang, CheonAn, CungNam, 331-825, South Korea
2 Bio Photonics laboratory, APRI, GIST, 123, CheomDan-GwaGi RD., BukGu, GwangJu, 500-712, South Korea
This paper propose an optical structure to generate trigger signals for optical coherence tomography (OCT) using backward light which is usually disposed. The backward light is called backward amplified stimulated emission generated from semiconductor optical amplifier (SOA) when using swept wavelength tunable laser (SWTL). A circulator is applied to block undesirable lights in the SWTL instead of an isolator in common SWTL. The circulator also diverts backward amplified spontaneous lights, which finally bring out trigger signals for a high speed digitizer. The spectra of the forward lights at SOA and the waveform of the backward lights were measured to check the procedure of the trigger formation in the experiment. The results showed that the trigger signals from the proposed SWTL with the circulator was quite usable in OCT.
© Owned by the authors, published by EDP Sciences, 2015
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