01/04/2006 internal report1 Properties of VCSELs (80 µm) Y. Tanguy, M. Schulz-Ruhtenberg 1, T. Ackemann SUPA, Department of Physics University of Strathclyde Glasgow, Scotland, UK 1 Institut für Angewandte Physik, Universität Münster, Münster, Germany

2 Devices p mirror: 33 stacks GaAs-Al 0.88 Ga 0.12 As + metal mirror n mirror: 21.5 stacks GaAs-Al 0.88 Ga 0.12 As QW: 3 In 0.2 Ga 0.8 As, width 8 nm, barrier 10 nm substrate: 208 µm +/- 5 µm AR-coating: Si3N4, /4, n=1.89

3 Characterization UP received from UP: July 2005 order: product: ULM TN-H56OOP(80µm) wafer: 00000_156D

4 Solitary laser- Spatial characteristics Near-field 60mA Far-field 60mA  On axis emission: “broad” features at perimeter of laser.  Off-axis emission: small-scale standing wave along perimeter.  Indicates that the maximum gain is blue shifted with respect to the longitudinal cavity resonance. 28°

5 Solitary laser: LI-curves

6 Solitary lasers: Spectra On-axis emission Off-axis emission in qualitative agreement with expectations for tilted waves

7 Length scales (circular) Stripes: –Near-field 253±8 –Far-field 258±11 Length scales –Wavelength in NF: L = 0.91µm –Wave number: q = 2  /2L = /µm –Measured from FF: q = /µm NF FF T=10°C, I=56mA, ‘y‘

8 Solitary laser - lengthscales

9 Fourierspectra (circular) 80mA „x“ „y“ Fourier spectrumOptical spectrum wave number shift 0.7 /µm /20K from 2. to 1.3 /µm changes detuning from 1.3 to 3.6 nm shift about 2.1 nm/20K or 0.1 nm/K expected about 0.18 nm/K if due to shift of gain offset or does InGaAs shifts less in GaAs ?

10 Fourierspectra (circular) 80mA „x“ „y“ Fourier spectrum

11 Fourierspectra (circular) 10°C „x“ „y“ Fourier spectrumOptical spectrum (leider wird in den eps- grafiken immer geglättet und ich weiß nicht wieso...) current

12 Fourierspectra (circular) 10°C „x“ „y“ Fourier spectrum current