NSF Award
2320265
Photons, particles of light, can travel across long distances with very high efficiency, especially when propagating in very low loss fiber-optical cables. Therefore, photons are used as information carriers of choice for optical communication technology that forms the backbone of the internet. Integrated photonic chips - integrated photonics for short - consisting of many micron-scale optical devices, have emerged as an essential technology required to encode information in a photon’s color, polarization, shape, and position. Beyond optical communications, integrated photonics has enabled a wide range of applications with significant societal impact, including environmental monitoring, bio-medical imaging, machine vision, and high-performance computing. These applications crucially rely on the ability to efficiently interface “micro-world” of integrated photonic chips with “macro-world” of optical fibers. In the laboratory setting, this is achieved using bulky, expensive, and high-precision positioners, which renders the system challenging to use in real-world applications. Photonic wire bonding (PWB), the process of permanently attaching an optical fiber to a photonic chip, is ideally suited to overcome this limitation and improve the performance and usability of the integrated photonics. Furthermore, it can also make these systems accessible to many under-resourced communities (e.g. small colleges, high schools) who may not have access to state of the art laboratory equipment. This Major Research Instrumentation (MRI) award is supporting the acquisition of a PWB system by Vanguard Automation. The tool will be placed in a shared clean room facility - Center for Nanoscale Systems at Harvard, member of NNCI network - where it will be available to many academic and industrial users. Therefore, the tool will enable many scientific breakthroughs, stimulate technological advancements and entrepreneurship, and help train a diverse and photonic-savvy workforce. <br/><br/>Modern chip-scale photonic systems consist of many optical devices, including waveguides, resonators, modulators, switches, lasers and detectors, realized in a variety of photonic materials and has enabled applications ranging from optical communications and computation on one end, to sensing and precision measurement on the other. The outstanding challenge for integrated photonics is that of efficiently getting light on- and off-chip. Due to the large optical mode mismatch between sub-micron scale on-chip optical waveguides and commercially available optical fibers, featuring optical mode diameters exceeding ten microns, much of the light is lost when light passes from the waveguide to the fiber. This is particularly true for applications that require low temperature operation (e.g. inside cryostat or dilution refrigerator), operation in fluids (e.g. in sensors), scalability (e.g. 10s or 100s devices to be connected at the same time), or robustness to vibrations. Recently, photonic wire bonding, an optical equivalent to electrical wire bonding ubiquitous in electrical circuits, has emerged as a promising technique to create efficient and permanent connections between photonic devices on different platforms, or with fibers or lasers. In this approach, 3-D polymer waveguides are fabricated in situ to bridge the gap between photonic circuits located on different chips, or between the chip and fiber or laser. This technique not only enables scalable, highly efficient, and low loss interface between optical chips and optical fibers, but also allows for the realization of compact hybrid devices that combine different materials. The PWB tool will facilitate successful completion of a large number of ongoing research programs focused on development of new types of chip-scale lasers (including pulsed ones), frequency combs and single-photon sources, for example, and their application in microwave photonics, optical communication and computing, precision measurements of time and distance, environmental monitoring, quantum communication and computation. The tool will also enable new opportunities by the ability to perform long term, stable measurements.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
