Current spreading in apertured vertical-cavity lasers

Scaling of the threshold current density in apertured vertical cavity lasers is limited by scattering losses, current spreading, and carrier diffusion. We consider the contributions of all three effects, but focus on current spreading. We analyze a vertical cavity laser (VCL) with low scattering losses so the scaling of the threshold current density is dominated by current spreading under the aperture. We show that a simple analytic estimate (appropriate for circular geometry) for the increase in threshold matches experimental data extremely well without any fitting parameters. One can also conveniently apply the estimate of current spreading to VCLs with double apertures or multiple layers of different resistivities. We also show that current spreading should only negligibly reduce the differential efficiency as implied by experiment.

[1]  William Paul Dumke.  Current thresholds in stripe-contact injection lasers , 1973 .

[2]  D. Deppe,et al.  Sub-40 μA continuous-wave lasing in an oxidized vertical-cavity surface-emitting laser with dielectric mirrors , 1996, IEEE Photonics Technology Letters.

[3]  W. B. Joyce,et al.  Steady‐State Junction‐Current Distributions in Thin Resistive Films on Semiconductor Junctions (Solutions of ▿2v = ±ev) , 1970 .

[4]  S. Adachi,et al.  Properties of Aluminium Gallium Arsenide , 1993 .

[5]  Brian Thibeault,et al.  Scattering losses from dielectric apertures in vertical-cavity lasers , 1997 .

[6]  Brian Thibeault,et al.  Vertical-cavity surface-emitting lasers for free-space interconnects , 1996, Photonics West.

[7]  Won-Tien Tsang,et al.  The effects of lateral current spreading, carrier out‐diffusion, and optical mode losses on the threshold current density of GaAs‐AlχGa1−χAs stripe‐geometry DH lasers , 1978 .

[8]  Kohroh Kobayashi,et al.  A GaAs-AlxGa1-xAs Double Heterostructure Planar Stripe Laser , 1973 .

[9]  Brian Thibeault,et al.  Electrical and optical losses in dielectrically apertured vertical-cavity lasers , 1997, Photonics West.

[10]  R. Nagarajan,et al.  Transport limits in high-speed quantum-well lasers: experiment and theory , 1992, IEEE Photonics Technology Letters.

[11]  Kent D. Choquette,et al.  High-frequency modulation of oxide- confined vertical cavity surface emitting lasers , 1996 .

[12]  Niloy K. Dutta,et al.  Analysis of current spreading, carrier diffusion, and transverse mode guiding in surface emitting lasers , 1990 .

[13]  L. Coldren,et al.  Diode Lasers and Photonic Integrated Circuits , 1995 .

[14]  Brian Thibeault,et al.  Estimation of scattering losses in dielectrically apertured vertical cavity lasers , 1996 .

[15]  K. Bertilsson,et al.  High-speed characteristics of low-optical loss oxide-apertured vertical-cavity lasers , 1997, IEEE Photonics Technology Letters.

[16]  Chao-Kun Lin,et al.  Confinement effects of AlAs native-oxide apertures buried in quantum well lasers , 1996, Conference Digest. 15th IEEE International Semiconductor Laser Conference.

[17]  L. Coldren,et al.  Reduced optical scattering loss in vertical-cavity lasers using a thin (300 /spl Aring/) oxide aperture , 1996, IEEE Photonics Technology Letters.

[18]  R. F. Kopf,et al.  N‐ and P‐type dopant profiles in distributed Bragg reflector structures and their effect on resistance , 1992 .