are they useful for high-capacity single-mode fiber datacom?
Gigabit/s-LANs with 0.85 micrometers vertical cavity surface emitting lasers (VCSELs) are now going into the market. But, their link length is limited to be shorter than 500 m due to modal dispersion of employed multi-mode fibers and various modal problems should be considered in system design. The next step will be to develop long wavelength VCSELs matching to a single model fiber with longer link lengths of several km and higher data rates. Long wavelength single mode fiber datacom should be advantageous because of avoiding modal noise and relaxing eye safe issues. Recently, we demonstrated a 1.2 micrometers wavelength highly strained GaInAs/GaAs quantum well edge emitting laser, which exhibits reasonably low threshold and excellent temperature characteristics. The threshold current is as low as 13 mA for an as-cleaved 5 X 380 micrometers laser. A characteristic temperature T0 under pulsed operating is as high as 140 K. This is the record high T0 in 1.2-1.3 micrometers wavelength ban
