3D-Printed Optics for Wafer-Scale Probing

Abstract

Mass production of photonic integrated circuits requires high-throughput wafer-level testing. We demonstrate that optical probes equipped with 3D-printed elements allow for efficient coupling of light to etched facets of nanophotonic waveguides. The technique is widely applicable to different integration platforms.

Packaging of micro-lens arrays to photonic integrated circuits using beam shape evaluation

“…to take advantage of contactless optical coupling using an expanded beam connector (as in figure 2(a)). Alternatively, the FAs can be equipped with 3D-printed light-turning lenses [34] for an even more simplified geometry.…”

High Density Multi-Channel Passively Aligned Optical Probe for Testing of Photonic Integrated Circuits

“…. ., [15][16][17][18][19][16][17][18]. Fingers 1 and 17 are not used in this experiment, so 15 pairs (30 connections) were tested.…”

“…Edge-coupled devices have the advantage of broadband optical response, but access to the waveguide is not available until after the chips have been singulated from the wafer. Since the mode size of a standard single-mode fiber (SMF) and the waveguide may differ significantly (typically a factor [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], either mode-size converters are required or sub-micron alignment may be needed, or a combination of both. Grating couplers couple out-of-plane to a near-vertical direction and are manufacturable in thin membranetype high-contrast waveguides, typically in Si-based integration technologies.…”

“…Although more advanced solutions using multiple port optical interposers for vertical coupling combined with electrical probing have been reported [15], these still rely on grating couplers, require active alignment and are not suited for edge emitting photonic integration platforms. For multi-port testing and on-wafer probing, probe heads have been reported using technology with a total internal reflection element that redirects the light collected from a trench in front of on-wafer waveguides [16], [17]. These approaches tackle the multiple port issue and the possibility to run optical tests before separation of the individual PICs but the alignment between the probe and the PIC waveguides is challenging because sub-micron active alignment on at least three axes is required to achieve optimum optical power coupling.…”

3D-printed aspherical lens with moth-eye anti-reflection structure

“…In particular, 3D-printed micro-lens would be useful for optical devices because it could significantly reduce lens size, and it could be attached to device I/O ports directly. Many applications of 3D-printed lens have been reported, such as tolerance expansion of lasers and fibers 1 , lenses for wafer scale probing 2 , and beam shapers for optical phased arrays 3 .…”