We describe a photonic quantum ring (PQR) laser device of three dimensional toroidal whispering gallery cavity. We
have succeeded in fabricating the first genuine mega-pixel laser chips via regular semiconductor technology. This has
been realized since the present injection laser emitting surface-normal dominant 3D whispering gallery modes (WGMs)
can be operated CW with extremely low operating currents (μA-nA per pixel), together with the lasing temperature
stabilities well above 140 deg C with minimal redshifts, which solves the well-known integration problems facing the
conventional VCSEL. Such properties unusual for quantum well lasers become usual because the active region,
involving vertically confining DBR structure in addition to the 2D concave WGM geometry, induces a 'photonic
quantum ring (PQR)-like' carrier distribution through a photonic quantum corral effect. A few applications of such
mega-pixel PQR chips are explained as follows: (A) Next-generation 3D semiconductor technologies demand a strategy
on the inter-chip and intra-chip optical interconnect schemes with a key to the high-density emitter array. (B) Due to
mounting traffic problems and fatalities ITS technology today is looking for a revolutionary change in the technology.
We will thus outline how 'SLEEP-ITS' can emerge with the PQR's position-sensing capability. (C) We describe a recent
PQR 'hole' laser of convex WGM: Mega-pixel PQR 'hole' laser chips are even easier to fabricate than PQR 'mesa'
lasers. Genuine Laguerre-Gaussian (LG) beam patterns of PQR holes are very promising for biocell manipulations like
sorting mouse myeloid leukemia (M1s) cells. (D) Energy saving and 3D speckle-free POR laser can outdo LEDs in view
of red GaAs and blue GaN devices fabricated recently.
Lord Rayleigh's 2 dimensional (2D) whispering gallery mode (WGM) is based upon 2D total internal reflection (TIR)
while 3D whispering cave mode (WCM) is based upon 3D TIR. 3D WCM is however irreducible to 2D WGM: The 2D
WGM is confined to a thin microdisk with a cylindrical symmetry solvable via Bessel function analysis while the 3D
WCM is confined to a virtual toroid with a circular helix symmetry not reducible to a simple 2D symmetry. The 3D
WCM laser is surface-normal dominant and has no in-plane resonance while the 2D WGM laser is in-plane dominant.
Apart from the regular 2D WGM, the 3D WCM's major polarization state favors a strong carrier-photon coupling for the
carriers in the planar quantum wells, such that the powerful transient coupling generates photonic quantum rings (PQRs),
or concentric quantum rings with a half-wavelength pitch of imminently recombinant carriers, i.e., a photonic quantum
corral effect. This feature is responsible for the low threshold currents and thermally stable spectra, which opens the way
for easy optical mega-pixel ('Omega') chip fabrications.
For the GaAs device size less than 1 μm, the increasing intermode spacing leads to a single eigenmode PQR laser with a
record low threshold current of 300 nA.. Moreover PQR 'holes', or microholes in the quantum well plane, give rise to an
unusual 'convex' WCM laser via gain guiding effects. Mega-pixel PQR 'hole' laser chips are easier to fabricate than
PQR 'mesa' chips, and both will be useful for optoelectronic VLSI, ITS, and biocell sorting.
We report for the first time angle-dependent multiple- wavelength emissions over 30 nm range from a toroidal cavity, which is a photonic quantum ring laser naturally formed in a VCSEL structure, with an ultralow threshold approaching the (mu) A-range consistent with Yariv's quantum wire view.
A successful fabrication of semiconductor optical switch, similar in function to the self- electro-optic effect devices, is reported for the first time from MOCVD-grown GaAs/AlGaAs low barrier quantum well pin diodes (Al fraction, x equals 4%). A reflective 16 X 8 switch array and its performance are also reported. The maximum contrast ratio was found to be 2.9:1 at 5 V bias.
GaAS I AIGaAs multiple quantum well structures grown by low pressure metal organic chemical vapor deposition have been studied using electron microscopy photoluminescence photoabsorption and photocurrent spectroscopies. Room temperature exciton doublets quantum confined Stark shifts were observed and analysed.