Single quantum dot controlled lasing effects in high-Q micropillar cavities

Abstract

Lasing effects based on individual quantum dots have been investigated in optically pumped high-Q micropillar cavities. We demonstrate a lowering of the threshold pump power from a off-resonance value of 37 microW to 18 microW when an individual quantum dot exciton is on-resonance with the cavity mode. Photon correlation studies below and above the laser threshold confirm the single dot influence. At resonance we observe antibunching with g((2))(0) = 0.36 at low excitation, which increases to 1 at about 1.5 times the threshold. In the off-resonant case, g((2))(0) is about 1 below and above threshold.

Submicrometer diameter micropillar cavities with high quality factor and ultrasmall mode volume

“…In order to set the resonating wavelength at 637nm, the thickness of each taper segment is precisely tuned to w 1 =215.3nm, w 2 =202.4nm, w 3 =191.0nm, and w 4 =180.8nm. The resulting mode has a Q factor of 250,000 and a mode volume of 0.07(λ/n) 3 , which represents at least three orders of magnitude enhancement of Q/V compared to any previous micropillar designs. As shown in Fig.…”

“…recently for large diameter (d=4µm) pillars, resulting in a relatively large mode volume [V>50(λ/n) 3 ] [6]. However, for applications in cQED, coupling between an emitter and a photon localized in the cavity requires a large Rabi frequency g that is proportional to 1/ V .…”

Emission properties of nanolasers during the transition to lasing

“…1-3 Among the driving forces for substantial miniaturization of lasers are technological applications, such as optical interconnects for information processing and communications, where reducing the power consumption is a priority. 4 From a research viewpoint, such efforts are motivated by a new quantum limit that is reachable with nanolasers consisting of a few emitters [5][6][7] or even a single emitter [8][9][10] and low intracavity photon numbers sustained by stimulated emission. 11 Entering the regime of cavity quantum electrodynamics (CQED), nanolasers can provide non-classical light for applications in quantum information.…”

Semiconductor Cavity Quantum Electrodynamics with Single Quantum Dots

“…The exploitation of single semiconductor quantum dots (QDs) as zero-dimensional light emitters and artificial atoms and their integration into optical resonators has led to an entire new generation of highly sophisticated devices in semiconductor systems. For instance, efficient single photon sources [2][3][4][5][6][7] and few to single QD lasers [8][9][10][11] have been extensively researched. Furthermore, the manipulation of a single electron spin in a self-assembled QD [12] is an important first step toward cavity based future quantum information processing schemes based on QDs [13,14].…”