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Laser Optics & Photonics and Atomic & Plasma Science 2018
J u l y 1 6 - 1 7 , 2 0 1 8
P r a g u e , C z e c h R e p u b l i c
Page 30
American Journal of Computer Science and Information Technology
ISSN: 2349-3917
E u r o S c i C o n J o i n t E v e n t o n
Laser Optics & Photonics and
Atomic & Plasma Science
T
he photonic quantum ring (PQR) lasers consist of cylindrical mesas of multi-quantum well (MQW) active region between top
and bottom DBR structures. PQRs create the resonant double helix standing waves (CW and CCW) of the 3D donut cavity
because it is 3D version of Lord Rayleigh’s 2D whispering gallery mode (WGM). The room-temperature PQR thresholds are in the
micro-ampere range for active diameters less than 20μm. The GaAs PQR then exhibits 3D spectra of apex-angle-dependent blue-
shifts in the 20–30 nm range (795-765nm major peaks) as shown in Fig.1, implying that it is possible to extend continuously the
PQR’s tunable frequency ranges in 20nm steps from 700 to 980nm, to cover almost all interesting ionic IR frequency ranges, quite
different from the usual functional near-infrared spectroscopy (FNIRS) being confined to single or few frequencies, for instance,
for oxy/deoxy hemoglobin studies. Employing multiple 3D angle-tuning PQR measurements, we may go to hemodynamic or other
ionic transport studies for various brain/heart diseases in the near future.
Figure: 1
The active MQWs between the two DBR regions of the PQR device described in the beginning generate spectral peaks
of both PQR and VCSEL resolved with a microprobe made of a tapered single modefiber and a spectrum analyzer (HP model
70951A), where the angle-dependent PQR emissions are inseparable from that of the VCSEL, because of data overlapping due to
a monitoring microscope placed right above the device)
A new spectroscopy based upon 3D photonic quantum ring
lasers for non-invasive and portable brain/heart disease
diagnostic techniques
O’Dae Kwon
POSTECH, South Korea
O’Dae Kwon, Am J Compt Sci Inform Technol 2018, Volume 6
DOI: 10.21767/2349-3917-C1-002