A semiconductor device includes an upper and lower mirror. At least one active region for light generation is between the upper and lower mirror. At least one cavity spacer layer is between at least one of the upper and lower mirror and the active region. The device includes an inner mode confinement region and an outer current blocking region. A depleted heterojunction current blocking region (DHCBR) including a depleting impurity is within the outer current blocking region of ≥1 of the upper mirror, lower mirror, and the first active region. A middle layer including a conducting channel is within the inner mode confinement region that is framed by the DHCBR. The DHCBR forces current flow into the conducting channel during normal operation of the light source.