Single-mode surface-emitting quantum-cascade lasers

Pflügl, C.; Austerer, M.; Schrenk, W.; Golka, S.; Strasser, G.; Green, R. P.; Wilson, L. R.; Cockburn, J. W.; Krysa, A. B.; Roberts, J.S.

doi:10.1063/1.1929070

Cited by 55 publications

(22 citation statements)

References 14 publications

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“…Although the latter also achieves small beam divergence in one direction and high output power 20 , many applications require an edge-rather than surface-emitting geometry. The advantage of the plasmonic collimation scheme lies in its flexibility; it can be upgraded to a 2D periodic structure that can collimate light in both the vertical and lateral directions, thus achieving complete beam collimation, and can be modified to control the polarization of the laser.…”

Section: Discussionmentioning

confidence: 99%

Small-divergence semiconductor lasers by plasmonic collimation

et al. 2008

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Surface plasmons offer the exciting possibility of improving the functionality of optical devices through the subwavelength manipulation of light. We show that surface plasmons can be used to shape the beams of edge-emitting semiconductor lasers and greatly reduce their large intrinsic beam divergence. Using quantum cascade lasers as a model system, we show that by defining a metallic subwavelength slit and a grating on their facet, a small beam divergence in the laser polarization direction can be achieved. Divergence angles as small as 2.48 8 8 8 8 are obtained, representing a reduction in beam spread by a factor of 25 compared with the original 9.9-mm-wavelength laser used. Despite having a patterned facet, our collimated lasers do not suffer significant reductions in output power ( 100 mW at room temperature). Plasmonic collimation provides a means of efficiently coupling the output of a variety of lasers into optical fibres and waveguides, or to collimate them for applications such as free-space communications, ranging and metrology.

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Section: Discussionmentioning

confidence: 99%

Small-divergence semiconductor lasers by plasmonic collimation

et al. 2008

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“…Considering the fundamental characteristic of transverse magnetic (TM) polarization defined by the intersubband transitions, a QCL is not suitable for conventional vertical cavity surface-emitting configuration. Consequently, second-order DFB gratings [4][5][6] or photonic crystal (PhC) resonators [7] are usually incorporated into the QCLs to achieve surface emission. However, the intrinsically in-plane emission characteristic of QCL leads to the PhC device low light extraction efficiency.…”

Section: Introductionmentioning

confidence: 99%

High-Power Surface-Emitting Surface-Plasmon-Enhanced Distributed Feedback Quantum Cascade Lasers

Chen

Liu

Guo

et al. 2012

IEEE Photon. Technol. Lett.

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Room temperature operation of surface-emitting single-mode distributed feedback quantum cascade lasers (QCLs) operating at a wavelength around 8.5 µm is presented. The record output peak powers of 3.85 W at 160 K and 1.06 W at 300 K were obtained by an optimum grating design. A two-lobed farfield pattern with a separation of 0.35°along the waveguide was observed. It is an important step to realize the practical application of surface-emitting QCLs in mid-infrared spectral range for high power in optical circuit integration.

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“…The most popular design is a surface emitting configuration via a second-order grating, which features a small divergence angle inversely proportional to the length of the grating. This strategy has been successfully applied to mid-IR [11][12][13][14] and THz [15,16] ridge QCLs and to surface-emitting ring or disk QCLs [17][18][19]. A similar approach is based on surface-emitting QCLs with 2D photonic-crystal cavities [20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Beam engineering of quantum cascade lasers

Wang

Capasso

2011

Laser & Photonics Reviews

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This paper reviews beam engineering of mid-infrared and terahertz quantum cascade lasers (QCLs), based on two approaches: designer plasmonic structures and deformed microcavities. The plasmonic structures couple laser emission into surface waves and control the laser wavefront in the nearfield, thereby greatly increasing beam collimation or introducing new functionalities to QCLs. The plasmonic designs overall preserve laser performance in terms of operating temperature and power output. The deformed microcavity QCLs operate primarily on whispering-gallery modes, which have much higher quality factors than other modes, leading to lower threshold current densities. Cavity deformations are carefully controlled to greatly enhance directionality and output power.

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Single-mode surface-emitting quantum-cascade lasers

Cited by 55 publications

References 14 publications

Small-divergence semiconductor lasers by plasmonic collimation

Small-divergence semiconductor lasers by plasmonic collimation

High-Power Surface-Emitting Surface-Plasmon-Enhanced Distributed Feedback Quantum Cascade Lasers

Beam engineering of quantum cascade lasers

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