Suspended BGaP-on-Si disk resonators (SEM) (Top-view)
Patterned with HSQ electron beam lithography using BGaP (220nm) on silicon substrate. The 5um dia. BGaP disks are undercut with a XeF2 vapor etch.
Gallery
A collection of optical and scanning electron micrographs of hybrid photonic devices that I designed and fabricated at the WNF during my graduate studies.
I utilized electron beam lithography and RIE plasma etching processes to create devices with minimum feature sizes as small as 40 nm.
Suspended BGaP-on-Si disk resonators (SEM) (Angled-view)
Patterned on epitaxially grown BGaP (220nm) on silicon substrate. The 5um dia. BGaP disks are undercut with a XeF2 vapor etch.
Zoom-in on the suspended BGaP-on-Si disk resonators (SEM) (Angled-view)
Patterned on epitaxially grown BGaP (220nm) on silicon substrate. The 5um dia. BGaP disks are undercut with a XeF2 vapor etch.
Arrays of suspended BGaP 1-D photonic crystal cavities (Optical)
The suspend BGaP appears yellow and BGaP-on-Si is blue. The input and output gratings glow green. Each pair of gratings is connected by a photonic crystal waveguide.
1-D Photonic crystal cavity with input and output gratings (SEM) (Top-view)
The BGaP is patterned by E-Beam lithography and RIE plasma etching. The BGaP beams are released from the underlying Si substrate by a vapor etch XeF2 process.
Zoom-in of a 1-D Photonic crystal cavity (SEM) (Top-view)
The devices are designed for stamp-transfer onto a diamond substrate that hosts solid-state qubits (silicon vacancy centers).Smallest hole size here is ~35nm.
An array of suspended photonic crystal devices with accompanying support structures (SEM) (Angled-view)
Angled SEM emphasizes the large undercut beneath the 220nm thick BGaP photonic structures.
Zoom-in of a 1-D suspended photonic crystal cavity beam (SEM) (Angled-view)
The beams are 220nm thick and 360nm wide.
An array of ring resonators designed for SHG frequency conversion (Optical)
The GaP devices (green) are fabricated on a silicon nitride substrate. The 250nm GaP membrane is wet transferred onto the nitride.
An array of ring resonators designed for SHG frequency conversion (SEM)
Zoom-in of a SHG ring resonator (SEM)
The two sets of gratings and coupling regions are designed for 1550nm (input) and 775nm (SHG output).
Zoom-in on some test gratings (SEM)
The gratings are connected by a small section of waveguide. These devices are designed for characterization of the grating transmission spectra. The narrowest slot in the grating has a width of 40nm.
An array of waveguide coupled disk resonators patterned on GaP-on-SiNx substrate (Optical)
Disk resonators patterned with HSQ e-beam resist spun on a GaP-on-silicon nitride substrate. The 250nm GaP layer was transferred by wet liftoff from a GaP-on-AlGaP sample.
Zoom-in on waveguide coupled disk resonators in an add-drop coupling configuration patterned on GaP-on-SiNx substrate (Optical)
The smallest disks are 1um in diameter, with the waveguide-disk coupling separation ~100nm.
A photonic device with several 2um diameter disk resonators (SEM)
The input, drop and transmission grating couplers are shown etched into the GaP material (GaP-on-SiNx substrate). The smallest slot in the grating is ~60nm wide.
A photonic device with several 2um diameter disk resonators (SEM) (Angled-view)
Devices are etched into GaP (GaP-on-SiNx substrate).
A photonic device with several 1um diameter disk resonators (SEM)
Devices are etched into GaP (GaP-on-SiNx substrate).
A large array of inverse-designed photon extractors patterned on GaP-on-diamond substrate (Optical)
Inverse designed photon extractor patterned on HSQ e-beam resist spun on a GaP-on-diamond substrate. The 250nm GaP layer (yellow) was transferred by wet liftoff from a GaP-on-AlGaP sample.
Zoom-in on an array of inverse-designed photon extractors etched into the GaP (Optical)
RIE etching transfers the pattern into the GaP layer, without etching into the diamond substrate.
Inverse-designed photon extractors etched into GaP on diamond substrate (SEM) (Angled-view)
These photonic devices are evanescently coupled to single nitrogen-vacancy solid-state qubits ~100nm deep in the diamond substrate
Zoom-in on a inverse-designed photon extractors etched into GaP on diamond substrate (SEM) (Top-view)
The smallest features are 45nm diameter pillars.
Colorized SEM of an inverse-designed photon extractor
Layers: HSQ E-Beam resist (blue), GaP (pink), Diamond (grey)
An array of waveguide coupled inverse designed resonators patterned on GaP-on-oxide substrate (Optical)
Inverse designed resonators for second harmonic generation, patterned with HSQ e-beam resist spun on a GaP-on-oxide substrate. The 250nm GaP layer was transferred by wet liftoff from a GaP-on-AlGaP sample.
Inverse designed resonators coupled to waveguides (SEM) (Angled-view)
GaP-on-oxide inverse SHG photonic devices
Zoom-in of an inverse designed resonator coupled to waveguides (SEM) (Top-view)
GaP-on-oxide inverse SHG photonic devices
Zoom-in of an inverse designed resonator coupled to waveguides (SEM) (Angled-view)
GaP-on-oxide inverse SHG photonic devices
Zoom-in on a grating coupler region showing vertical etch sidewalls (SEM) (Angled-view)
The two layers are HSQ resist (top) and GaP (bottom) on a silicon oxide substrate
Grating coupled ring resonators (SEM) (Angled-view)
Patterned on epitaxially grown GaP (150nm) on AlGaP (400nm) on GaP substrate.
Grating coupled disk resonators (SEM) (Angled-view)
Patterned on epitaxially grown GaP (150nm) on AlGaP (400nm) on GaP substrate.
Zoom-in on the grating coupled disk resonators (SEM) (Angled-view)
The different material layers (HSQ resist, GaP, AlGaP, GaP substrate) are visible. A custom RIE etch process (Ar\Cl2\N2) was developed for the high aspect ratio etched structures.
A colorized SEM of a waveguide coupled superconducting single photon detector
Layers (from top to bottom): Gold contacts (yellow), Niobium nitride (blue) superconducting nanowire, GaP waveguides(pink), AlGaP substrate (grey). The nanowires are 80nm wide and 6nm thick.