Glass-molded optical interposers for wafer scale photonic integrated circuit packaging in 800G modules and co-packaged optics

Abstract

We report on glass-molded micro-optical interposers for single-mode fiber-to-PIC coupling fabricated in parallel by isothermal molding of 1-inch glass plates yielding over 100 arrays of 8 lenses each. Excess losses between PIC and singlemode fiber are below 1 dB. In addition to allowing a narrow package footprint, beam transformation maps mode profiles between fibers and surface couplers, and, in case of grating couplers, can adapt the light incidence angle on a wavelengthspecific basis, facilitating packaging of PICs in CWDM and LAN-WDM modules. The interposers can be further extended to support polarization management and isolation by coating with polarization selective thin film stacks in MacNeille configuration, as well as wavelength multiplexing by coating with dichroic stacks. Using this technique, over 256 bidirectional transceiver channels can be packaged in the footprint of a single reticle.

Scalable PIC packaging and polarization control in CPO

“…1) [7]. For each parallel channel, a pair of lenses images and reshapes a beam between a single mode (SM) fiber and the PIC [8]. Over 1000 lenses can be molded in parallel in a ~20 minutes thermal cycle, resulting in a high throughput per press (Fig.…”