Lasing characteristics of GaInAsP-InP strained quantum-well microdisk injection lasers with diameter of 2-10 μm

In recent years there have been significant advances in the size and characteristics of small lasers, i.e. lasers with dimensions or modes sizes close to or smaller than the wavelength of emitted light. This work has primarily been led by innovative use of new materials and cavity designs. This article reviews some of the latest developments, particularly in metallic and plasmonic lasers, improvements in small dielectric lasers, and the emerging area of small bio-compatible/bioderived lasers. We examine the different approaches employed in small lasers to reduce size and how they lead to significant differences , particularly between metal and dielectric cavity lasers. We present potential applications for the various forms of small lasers and indicate where further developments are required.

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“…101 ), b, microdisk laser (from Ref. 102 ), c, photonic crystal laser (from Ref. 103 ), d, metallic non-plasmon mode laser (from Ref.…”

Section: Box: Exciton-polariton Lasersmentioning

confidence: 99%

Advances in small lasers

2014

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“…Threshold characteristics can be calculated, [1][2][3] and various research groups have sought to achieve lowthreshold operation by shrinking the device dimensions to reduce spontaneous emission into nonlasing modes; 4-6 the smallest microdisk laser reported having 1.6 m diameter. 5 Other groups have concentrated on optimizing the edge quality of their devices to improve the optical confinement, resulting in further reductions of the laser threshold. 7 In this letter we present an approach for decreasing the threshold in a large semiconductor disk (Rӷ ) based on reducing the amplified spontaneous emission ͑ASE͒ into competing nonlasing modes.…”

Section: K Kö Hlermentioning

confidence: 99%

Threshold reduction in pierced microdisk lasers

Backes

Cleaver

Heberle

et al. 1999

Applied Physics Letters

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GaAs microdisk lasers with holes pierced through the disk surface are investigated for their threshold characteristics. Disks are fabricated with either a single hole or two diametrically opposite holes at various distances from the disk outer edge. Even though the disk area is reduced by only 1%, we find that the lasing threshold for a disk with one hole is reduced by up to 50% compared to a disk with no hole. We attribute this reduction to the perturbation of nonlasing modes, which decreases the amplification of spontaneous emission in these modes and makes more carriers available to contribute to lasing. © 1999 American Institute of Physics. ͓S0003-6951͑99͒00301-0͔Semiconductor microdisk lasers are of interest for micron-scale low-threshold laser devices. Their laser modes approximate whispering-gallery ͑WG͒ modes, for which the high reflectivity at the curved disk boundary gives lowthreshold operation. The laser threshold is a function of the optical confinement, gain/absorption balance, scattering processes, and device dimensions. The optical confinement in these structures is high because of the large dielectric discontinuity between the disk and the surrounding air, while carrier absorption and scattering processes are difficult to modify. Threshold characteristics can be calculated, 1-3 and various research groups have sought to achieve lowthreshold operation by shrinking the device dimensions to reduce spontaneous emission into nonlasing modes; 4-6 the smallest microdisk laser reported having 1.6 m diameter. 5 Other groups have concentrated on optimizing the edge quality of their devices to improve the optical confinement, resulting in further reductions of the laser threshold. 7 In this letter we present an approach for decreasing the threshold in a large semiconductor disk (Rӷ ) based on reducing the amplified spontaneous emission ͑ASE͒ into competing nonlasing modes. We achieve this reduction by removing material from the interior of the disk, which reduces the photon lifetimes for modes with field in this region. Since the ASE depends on the photon lifetimes of the corresponding modes, fewer carriers emit into these modes, making more carriers available to contribute to lasing. The introduction of one small hole, comprising approximately 1% of the disk area, can reduce the laser threshold by a factor of 2. Figure 1 shows an electron micrograph of a typical microdisk structure with small holes etched through the top surface ͑Fig. 1͒. The disks contain four 10 nm GaAs quantum wells ͑QWs͒ separated by Al 0.28 Ga 0.72 As barriers, and are defined by electron-beam lithography and reactive ion etching. The pedestals ͑500 nm Al 0.65 Ga 0.35 As) are created by undercutting with a selective wet etch. Finally, the structures are passivated in ammonium sulphide and stabilized with a 30-nm-thick silicon nitride encapsulation. 8 The disks have a diameter of 12.6 m with 0.5 m square holes. Disks have been fabricated with one hole, or two holes placed opposite each other, separated from the disk outer edge by 0.5,...

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“…Size reduction of semiconductor lasers have in the past enabled studies of many rich physics on an ever decreasing spatial scale and the development of many technological applications. The quantum optics and laser physics community has witnessed dramatic progress over the past few decades in making increasingly smaller lasers using pure dielectric structures such as microdisk lasers, [15][16][17] photonic wire lasers, 18 photonic crystal (PC) lasers, [19][20][21][22] or nanowire lasers. 10,[23][24][25][26] These lasers represented the smallest lasers made of pure dielectric structures, and further miniaturization becomes exceedingly challenging.…”

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confidence: 99%