Film-level hybrid integration of AlGaAs laser diode with glass waveguide on Si substrate

Facet-embedded thin-film III–V edge-emitting lasers integrated with SU-8 waveguides on silicon

“…To realize low-power, portable, cost-effective chip-scale integrated systems, the laser power consumption must be minimized, the laser to waveguide coupling maximized, and the process technology simplified. Thus, the laser threshold current density, J th , should be low, the waveguide should be optimally coupled with the laser with minimal alignment requirements, and efficient heat sinking strategies should be implemented.Integration of TF-EELs with waveguides has been demonstrated on SiO 2 =Si [7], silicon-on-insulator [8,9], and with polymers [10][11][12], in addition to the characterization of photodetectors with polymer waveguides, for both Si photodiodes [13] and thin-film III-V metal-semiconductor metal photodetectors [11,14]. In [8][9][10][11], both p and n contacts are on the top of the laser, compromising current flow, and the interface between the laser and the substrate is thermally insulating, compromising thermal management.…”

“…Likewise,in [8], the simple cleaved hybrid laser has critical alignment requirements with other optical components. The TF-EELs end-fire coupled to waveguides [7,[9][10][11][12] all have an air gap between the laser and the waveguide, except for [9], in which the etched, not cleaved, EEL facet is embedded in the waveguide.In this Letter, we present the planar integration of a 980 nm TF-EEL with one cleaved facet embedded in a multimode SU-8 waveguide on a SiO 2 =Si substrate. This TF-EEL has top and bottom metal contacts, a p-side ridge, an n metal stripe for low J th operation, and a thermally conducting broad area metal contact bond to the SiO 2 =Si integration substrate.…”

“…Integration of TF-EELs with waveguides has been demonstrated on SiO 2 =Si [7], silicon-on-insulator [8,9], and with polymers [10][11][12], in addition to the characterization of photodetectors with polymer waveguides, for both Si photodiodes [13] and thin-film III-V metal-semiconductor metal photodetectors [11,14]. In [8][9][10][11], both p and n contacts are on the top of the laser, compromising current flow, and the interface between the laser and the substrate is thermally insulating, compromising thermal management.…”

“…In [8][9][10][11], both p and n contacts are on the top of the laser, compromising current flow, and the interface between the laser and the substrate is thermally insulating, compromising thermal management. In [7], the TF-EELs are placed in a trench in a slab waveguide, requiring precise control over etch depth and vertical alignment. Likewise, in [8], the simple cleaved hybrid laser has critical alignment requirements with other optical components.…”

“…Likewise, in [8], the simple cleaved hybrid laser has critical alignment requirements with other optical components. The TF-EELs end-fire coupled to waveguides [7,[9][10][11][12] all have an air gap between the laser and the waveguide, except for [9], in which the etched, not cleaved, EEL facet is embedded in the waveguide.…”