Room temperature continuous wave operation and controlled spontaneous emission in ultrasmall photonic crystal nanolaser

Abstract

Photonic crystal slab enables us to form an ultrasmall laser cavity with a modal volume close to the diffraction limit of light. However, the thermal resistance of such nanolasers, as high as 10(6) K/W, has prevented continuous-wave operation at room temperature. The present paper reports on the first successful continuous-wave operation at room temperature for the smallest nanolaser reported to date, achieved through fabrication of a laser with a low threshold of 1.2 muW. Near-thresholdless lasing and spontaneous emission enhancement due to the Purcell effect are also demonstrated in a moderately low Q nanolaser, both of which are well explained by a detailed rate equation analysis.

Tailoring the Lasing Modes in Semiconductor Nanowire Cavities Using Intrinsic Self-Absorption

“…However, the high-cost and complicated fabrication required, together with the weak coupling and the high optical losses between the two different cavities would offset any advantages. 19,20 Achieving low loss cavity modes with a high degree of mode selectivity, whilst not compromising on the quality and integrity of the nanostructures is therefore a significant and yet non-trivial challenge to overcome.…”

“…However, the high-cost and complicated fabrication required, together with the weak coupling and the high optical losses between the two different cavities would offset any advantages. 19,20 Achieving low loss cavity modes with a high degree of mode selectivity, whilst not compromising on the quality and integrity of the nanostructures is therefore a significant and yet non-trivial challenge to overcome.In this work, we present a new approach based on utilizing the intrinsic selfabsorption at the Urbach tail states to tailor the NW cavity lasing wavelength of semiconductor nanostructures. Importantly, this novel method allows one to achieve excellent mode selectivity spanning more than 30 nm with high cavity gain in highly crystalline, nominally undoped CdS NWs.…”

Localization effects on recombination dynamics in InAs/InP self-assembled quantum wires emitting at 1.5 μm

“…The InAs nanostructures were formed by the Stranski-Krastanov method depositing 1.7 monolayers (MLs) of InAs at a substrate temperature of 515 C with a growth rate of 0.1 ML/s. Due to the anisotropic character of the elastic relaxation in this system, QWRs arrays are naturally arranged along the [1][2][3][4][5][6][7][8][9][10] crystal direction as explained elsewhere. 9 Figure 1 shows an atomic force microscopy (AFM) image of an uncapped sample which exhibits a typical QWR width and height of 11 and 3.2 nm forming quasi-periodic structures (with pitch period around 18 nm).…”

“…The spontaneous and stimulated emission properties of quantum wells (QWs), quantum wires, and quantum dots (QDs) embedded in PhC microcavities have been reported. 5 As a result, the use of PhC technology merged with nanostructures has allowed a great enhancement of the electro-optical properties of semiconductor based devices like larger integration capacity, higher modulation rates, lower threshold laser operation, etc. From the fabrication point of view, embedding nano-structures into a PhC micro-cavity usually requires modifications of the grown process since the epitaxy structure must be adapted to the cavity design.…”

Room temperature, continuous-wave coupled-cavity InAsP/InP photonic crystal laser with enhanced far-field emission directionality

“…[1][2][3] Their small sizes bring the advantages of small on-chip footprint and potential of Purcell enhancement, which may lead to faster laser modulation and thresholdless lasing. [4][5][6] Room temperature (RT), continuous-wave (CW) operation is requisite for stable lasing characteristics and narrow linewidths and has been achieved with quantum dot, quantum wire, and quantum well (QW) materials using a variety of photonic crystal (PhC) cavity designs. [6][7][8] However, most of the wavelengthscale laser cavities are so far optimized for high quality factor (Q) and small effective volume (V eff ) in attempt to maximize the Purcell factor F p , but are not particularly designed for efficient light extraction.…”