Low-threshold operation of LCI-membrane-DFB lasers with Be-doped GaInAs contact layer

One of the promising candidates to solve a problem of a performance limitation of LSI is replacing electrical global wirings by on chip optical interconnections. We proposed and realized lateral-current-injection (LCI) type membrane DFB lasers for this purpose. In this paper, we report a new type LCI membrane DFB laser by introducing Be-doped GaInAs contact layer to the initial wafer structure so as to make simple fabrication of p-contact. As the result, a threshold current of as low as 3.8 mA, which was much lower than the previously reported value of 11 mA, was obtained for the stripe width of 1.5 μm and the cavity length of 250 μm.