Low-loss, cryogenically compatible optical fiber-to-chip interfaces for quantum and advanced classical photonic technologies

One of the major challenges associated with using chip-based photonic devices (lasers, detectors, etc.) is transferring light into and out of the chip (e.g., into optical fibers) without excessive loss. In the case of quantum photonics, many options to mitigate loss using conventional techniques (increasing signal power, re-sending lost data, etc.) are not allowed by the laws of quantum mechanics, meaning loss fundamentally degrades performance of quantum systems. This issue is amplified by the challenging environments that many quantum devices must tolerate – for example, assembly at room temperature followed by cooling to near-absolute zero for operation. To realize the full value of quantum photonic devices, engineers require a method of attaching optical fibers to photonic chips that is (a) low loss (<1 dB), and (b) resilient against environmental and/or mechanical effects (thermal expansion/contraction, vibration, etc.). This capability is broadly useful across the quantum and classical advanced photonics industries. One concrete example of a near-term use-case is quantum microwave- to-optical transducers. Transducers are chips (operating at ultra-low temperatures) that convert microwave photons into optical photons. This enables, for example, superconducting quantum computers to be optically networked similarly to classical computers, dramatically increasing their computational power and accelerating their timeline to cryptographic and military readiness. Getting quantum optical signals out of these chips at cryogenic temperatures drives the need for new, low-loss, resilient fiber-to-chip packaging because existing solutions are either high-loss, or are incompatible with cryogenic environments required by quantum technologies. Lightsynq's adiabatic tapered fiber packaging approach offers the ability to meet and exceed the loss requirements of quantum technologies while simultaneously being resilient against thermal effects that degrade the performance of other packaging approaches.