Quantum Cascade Surface-Emitting Photonic Crystal Laser

Abstract

We combine photonic and electronic band structure engineering to create a surface-emitting quantum cascade microcavity laser. A high-index contrast two-dimensional photonic crystal is used to form a micro-resonator that simultaneously provides feedback for laser action and diffracts light vertically from the surface of the semiconductor surface. A top metallic contact allows electrical current injection and provides vertical optical confinement through a bound surface plasmon wave. The miniaturization and tailorable emission properties of this design are potentially important for sensing applications, while electrical pumping can allow new studies of photonic crystal and surface plasmon structures in nonlinear and near-field optics.

Efficient power extraction in surface-emitting semiconductor lasers using graded photonic heterostructures

“…P ower extraction is a general and critical issue for the family of surface-emitting semiconductor lasers based on photonic crystal (PhC) resonators, be they 1D (second-order distributed feedback (DFB) lasers) [1][2][3][4] or 2D (surface-emitting PhC lasers) [5][6][7][8][9][10][11] . These devices operate on band-edge states of the photonic band structure, and can be classified as symmetric or antisymmetric, according to the spatial symmetry of their transverse electromagnetic field components.…”

Mid-Infrared Surface-Emitting Two Dimensional Photonic Crystal Semiconductor Lasers

“…Usually, in diode lasers, deep-etching induced surface recombination would substantially increase the leakage currents. (Colombelli F. , et al, 2003) But this serious obstacle does not affect in this case, because QCL are unipolar devices.…”

“…It has been proven that the gain enhancement is strongly correlated with the group velocity, which decreases rapidly in the vicinity of the photonic band edges. (Nojima, 1998) (Colombelli F. , et al, 2003) This work also characterized the threshold behavior of the device in figure 4. The lightoutput versus current characteristic of the device (red line) shows that the device fabrication was successful.…”

“…The first mid-IR surface emitting 2D photonic crystal QCL was realized in 2003. (Colombelli F. , et al, 2003) In this demonstration, the 2D arrays were fabricated with the values of lattice spacing a from 2.69 to 3.00 m, and the ratio of holes radius r to a from 0.28 to 0.32. As presented in figure 2B and figure 2C, the etched photonic crystal pattern penetrated through the active region down into the bottom substrate, which reduces the diffraction of radiation into the substrate and consequently provides strong in-plane optical feedback.…”

“…(Colombelli F. , et al, 2003) Therefore, the device should be classified as the bandedge mode photonic crystal lasers. Simply explaining, the optical gain is intensified by reducing the group velocity of light, supported by a basic relation about light amplification in which (H.C. Casey & Panish, 1978) …”