Low Threshold Current 1.3 µm InGaAsP Buried Crescent Lasers

The threshold current and beamwidth of the fundamental transverse mode have been examined of the buried crescent (BC) laser. The active region with less than 2.0 µm wide was successfully grown inside the channel prepared on the InP substate and the minimum threshold current of 8 mA has been obtained at room temperature (cavity length L =300 µm). An analytical expression for the beamwidth of far field patterns parallel to the junction plane (θ // ) has been obtained and it was confirmed that a good agreement is shown between the theoreitcal calculation and the experimental result.