A distributed feedback, DFB, interband cascade laser, ICL, or quantum cascade laser, QCL, having a low fill factor top contact, comprising: a laser ridge formed on a substrate, the laser ridge comprising: a superlattice bottom cladding layer; an active gain region disposed above the bottom cladding layer; a DFB grating layer having a DFB grating formed in a semiconductor layer disposed above the active gain region; a superlattice top cladding layer having a predetermined thickness disposed between the DFB grating layer and the active gain region; and a dielectric insulating film disposed on an upper surface of the DFB grating layer; and covering the upper surface of the laser ridge; wherein the dielectric insulating film has a predetermined plurality of repeated spaced-apart contact openings formed therein, running along a longitudinal length of the laser ridge, each of the contact openings extending laterally across the upper surface of the laser ridge perpendicular to a longitudinal axis of the laser ridge and being separated from a neighboring contact opening by a spacing having a width of at least 10 μm; the laser ridge further including a top metal contact disposed on an upper surface of the dielectric insulating film, the top metal contact being connected to a voltage source to provide an electrical contact to the laser ridge only in the areas exposed by the contact openings; wherein areas of the top of the laser ridge except for the contact openings are separated from the metal contact layer by the dielectric insulating film; and wherein a size and a spacing of the contact openings are configured to provide a predetermined fill factor of less than 100% in the top metal contact that provides a predetermined internal loss associated with an overlap between the lasing mode and the top metal contact. a laser ridge formed on a substrate, the laser ridge comprising: a superlattice bottom cladding layer; an active gain region disposed above the bottom cladding layer; a DFB grating layer having a DFB grating formed in a semiconductor layer disposed above the active gain region; a superlattice top cladding layer having a predetermined thickness disposed between the DFB grating layer and the active gain region; and a dielectric insulating film disposed on an upper surface of the DFB grating layer; and covering the upper surface of the laser ridge; a superlattice bottom cladding layer; an active gain region disposed above the bottom cladding layer; a DFB grating layer having a DFB grating formed in a semiconductor layer disposed above the active gain region; a superlattice top cladding layer having a predetermined thickness disposed between the DFB grating layer and the active gain region; and a dielectric insulating film disposed on an upper surface of the DFB grating layer; and covering the upper surface of the laser ridge; wherein the dielectric insulating film has a predetermined plurality of repeated spaced-apart contact openings formed therein, running along a longitudinal length of the laser ridge, each of the contact openings extending laterally across the upper surface of the laser ridge perpendicular to a longitudinal axis of the laser ridge and being separated from a neighboring contact opening by a spacing having a width of at least 10 μm; the laser ridge further including a top metal contact disposed on an upper surface of the dielectric insulating film, the top metal contact being connected to a voltage source to provide an electrical contact to the laser ridge only in the areas exposed by the contact openings; wherein areas of the top of the laser ridge except for the contact openings are separated from the metal contact layer by the dielectric insulating film; and wherein a size and a spacing of the contact openings are configured to provide a predetermined fill factor of less than 100% in the top metal contact that provides a predetermined internal loss associated with an overlap between the lasing mode and the top metal contact.