Université de Neuchâtel

MOCVD growth and characterization of AlGaInN multiple quantum well heterostructures and laser diodes

Bour, David P. ; Kneissl, Michael ; Hofstetter, Daniel ; Romano, Linda T. ; McCluskey, Matthew D. ; van de Walle, C. G. ; Krusor, B. S. ; Dunnrowicz, Clarence ; Donaldson, Rose M. ; Walker, J. ; Johnson, N. M.

In: Materials Science and Engineering B, 1999, vol. 59, no. 1-3, p. 33-38

We demonstrate room temperature, pulsed, current-injected operation of InGaAlN heterostructure laser diodes with mirrors fabricated by chemically assisted ion beam etching. The multiple quantum well devices were grown by organo–metallic vapor phase epitaxy on c-face sapphire substrates. The emission wavelengths of the gain-guided laser diodes were ~400 nm. The lowest threshold current density...

Université de Neuchâtel

Disordering of InGaN/GaN Superlattices After High-Pressure Annealing

McCluskey, Matthew D. ; Romano, Linda T. ; Krusor, B. S. ; Hofstetter, Daniel ; Bour, David P. ; Kneissl, Michael ; Johnson, N. M. ; Suski, T. ; Jun, J.

In: MRS Internet Journal of Nitride Semiconductor Research, 1999, vol. 4S1, no. G3.42, p. 1-6

Interdiffusion of In and Ga is observed in InGaN multiple-quantum-well superlattices for annealing temperatures of 1250 to 1400°C. Hydrostatic pressures of up to 15 kbar were applied during the annealing treatments to prevent decomposition of the InGaN and GaN. In as-grown material, x-ray diffraction spectra show InGaN superlattice peaks up to the fourth order. After annealing at 1400°C for 15...

Université de Neuchâtel

Characterization of InGaN/GaN-Based Multi-Quantum Well Distributed Feedback Lasers

Hofstetter, Daniel ; Thornton, Robert L. ; Romano, Linda T. ; Bour, David P. ; Kneissl, Michael ; Donaldson, Rose M. ; Dunnrowicz, Clarence

In: MRS Internet Journal of Nitride Semiconductor Research, 1999, vol. 4S1, no. G2.2, p. 1-6

We present a device fabrication technology and measurement results of both optically pumped and electrically injected InGaN/GaN-based distributed feedback (DFB) lasers operated at room temperature. For the optically pumped DFB laser, we demonstrate a complex coupling scheme for the first time, whereas the electrically injected device is based on normal index coupling. Threshold currents as low as...

Université de Neuchâtel

Realization of a complex-coupled InGaN/GaN-based optically pumped multiple-quantum-well distributed-feedback laser

Hofstetter, Daniel ; Romano, Linda T. ; Paoli, Thomas L. ; Bour, David P. ; Kneissl, Michael

In: Applied Physics Letters, 2000, vol. 76, p. 2337-2339

We demonstrate an optically pumped complex-coupled InGaN/GaN-based multiple-quantum-well distributed-feedback laser in the violet/blue spectral region. The third-order grating providing feedback was defined holographically and dry etched through a portion of the active region by chemically assisted ion-beam etching. Epitaxial overgrowth of the GaN waveguide completed the device structure without...

Université de Neuchâtel

Room-temperature pulsed operation of an electrically injected InGaN/GaN multi-quantum well distributed feedback laser

Hofstetter, Daniel ; Thornton, Robert L. ; Romano, Linda T. ; Bour, David P. ; Kneissl, Michael ; Donaldson, Rose M.

In: Applied Physics Letters, 1998, vol. 73, p. 2158-2160

We demonstrate room-temperature pulsed operation of an electrically injected InGaN/GaN-based distributed feedback laser with an emission wavelength of 403 nm. The threshold current of a 1000-µm-long and 20-µm-wide device was 3.2 A; corresponding to a threshold current density of 16 kA/cm2. The 3rd order grating providing feedback was defined holographically and dry etched into...

Université de Neuchâtel

Characterization of intra-cavity reflections by Fourier transforming spectral data of optically pumped InGaN lasers

Hofstetter, Daniel ; Romano, Linda T. ; Thornton, Robert L. ; Johnson, N. M.

In: Applied Physics Letters, 1997, vol. 71, p. 3200-3202

Fourier analysis of laser emission spectra just above threshold is used to evaluate the impact of structural defects on the emission from optically pumped InGaN lasers. By dry etching a 300-nm-deep groove into the surface of a laser bar, we have modified the emission spectrum of such a device in a controlled manner. The occurrence of sharp features in the Fourier transformed spectrum allowed the...

Université de Neuchâtel

Structural and optical properties of epitaxially overgrown third-order gratings for InGaN/GaN-based distributed feedback lasers

Romano, Linda T. ; Hofstetter, Daniel ; McCluskey, Matthew D. ; Bour, David P. ; Kneissl, Michael

In: Applied Physics Letters, 1998, vol. 73, p. 2706-2708

Laser-diode heterostructures of InGaAlN containing a third-order diffraction grating for distributed optical feedback have been examined with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The grating was defined holographically and etched by chemically assisted ion-beam etching into the upper GaN confinement layer of the laser structure. After the etch step, it...