Nov. 25, 2025
Co-Packaged Optics
The continuous pursuit of higher bandwidth and greater power efficiency in data centers and AI computers is accelerating the shift toward co-packaged optics (CPO), which integrates application-specific circuits (ASICs) and PICs in a single package. This paradigm shift introduces unprecedented challenges to the packaging process, particularly for testing complex optical devices and connecting optical fibers to PICs. As fiber counts per CPO package scale to thousands, traditional connector and cabling architectures will become obsolete. High-volume CPO deployments in AI computing systems are expected to launch in “scale-out” networks. Overcoming these packaging process challenges at a sufficiently low total cost of ownership would enable volumes to grow exponentially for “scale-up” networks between xPUs. This two-part article explores recent innovations that improve the supply chain and make it possible to assemble thousands of optical fibers into CPO packages. The first part addresses early supply chain challenges related to wafer-level testing at the optical I/O ports in PICs, which generally requires nanoscale accuracy and fast alignment of a fiber array unit (FAU). Detachable fiber-optic connectors simplify optical testing by preventing the need for permanently attaching fragile cable assemblies to optical engines in CPO packages. Detachability is practical with expanded-beam optics using refractive or reflective lenses between the PIC and optical fibers. The second part focuses on challenges introduced by expanded beams, which relax tolerances to translational offsets but also introduce new tolerances on angular misalignment. Here, the article will present intelligent alignment systems that must align all six degrees of freedom to find optimal placement of lenses and connector components while reducing alignment time. These new innovations are preparing the supply chain for high-volume production of CPO modules in scale-out and scale-up networks.
Key Technologies: Integrated Photonics, PICs, Co-Packaged Optics, Fiber Connects, Customized Beam Shaping, Focusing Mirrors, Photonic Packaging, Silicon, Optical Alignment, Motion Control
Microscopy
Correlative microscopy workflows, combining multiple imaging modalities, offer high value to structural biologists, leveraging the distinct benefits of optical and non-optical techniques. Correlative light-electron microscopy (CLEM) which combines fluorescence imaging and electron-based imaging, is a widely utilized correlative technique. This method is, by its nature, complementary: Fluorescence imaging in unmatched in its ability to discern regions of interest, and it does not interfere with the high-resolution images yielded via the EM method. This article overviews the complementary nature of this technology, looking at the advantages optimized fluorescence microscopy technology delivers to the correlative workflow. Temperature optimization, in sample prep and in imaging, is spotlighted, and cryo-fluorescence imaging is examined.
Key Technologies: Correlative microscopy, Correlative light-electron microscopy, fluorescence microscopy, temperature controlled microscopy imaging, cryo-fluorescence imaging, fluorophores, microscopy stages, cryo-stages, microscopy research.
Visible Sources
Prior to 2010, optical frequencies in the yellow and orange spectral range (~570-590 nm and ~590-625 nm) had been technology limited. This article will discuss the technology limitations at that time, the innovations that overcame these barriers, and the application windows that opened up as a result. The focus will be on near-infrared lasers using non-linear conversion processes to generate yellow light (fiber and DPSS lasers). The advantages of these lasers, as well as the resulting new applications, will be discussed. Applications will include flow cytometry, superresolution microscopy and ophthalmology. Citations from users will be solicited. In addition, an additional technology review of Raman fiber amplifiers will discuss how this further opened the potential for single frequency lasers in the yellow spectrum. A review of the application of single frequency yellow lasers including astronomy, atomic physics, and quantum will follow with user citations and future visions.
Key Technologies: Visible sources, yellow and orange lasers, NIR lasers, frequency conversion techniques (nonlinear conversion), fiber and diode-pumped solid-state lasers, lasers in flow cytometry, ophthalmology, and SR microscopy, Raman amplifiers, lasers in astronomy and adaptive optics, visible lasers in quantum.
Photonic MEMS
The convergence of MEMS and photonics has unlocked powerful applications possibilities — from precision lidar for automotive and industry, to high-density optical communications. However, manufacturing constraints continue to hinder commercial scalability. While the broader semiconductor industry has transitioned to 300-mm wafer production, much of the MEMS and photonics sector remains reliant on legacy 200-mm platforms. Advanced photonic devices require high-performance materials such as optical-grade low-pressure chemical vapor deposition silicon nitride and thick thermal oxides. These same devices often depend on process techniques not commonly used in conventional semiconductor manufacturing, further narrowing the pool of capable fabrication partners. This article explores the technical and infrastructure barriers limiting the scalability of photonic MEMS, and how new investments in flexible 300-mm MEMS manufacturing, are bridging critical gaps and paving the way for broader adoption and integration. Specifically, the article will examine the origins of the "MEMS-Photonics Crossroads," and, in that context, the barriers holding photonics (manufacturing) back. The role of role of thin films in photonics integration, and how a 300-mm MEMS platform, is poised to emerge as a game changer for established and emerging applications for manufacturing needs that remain unmet.
Key Technologies: Photonics and semiconductor manufacturing, semiconductor metrology, photonic chips, integrated photonics, MEMS, MEMS manufacturing, chips manufacturing, thin films, photolithography, photoresists, etching, deposition techniques for thin films
Photonic Sensors/Smart Sensors
EPIC's Ivan Nikitskiy examines the underlying technology and implications for the RETINA Project, a European initiative that initiative that promises to revolutionize the fields of healthcare, automotive, and agriculture through advanced photonics. RETINA aims to create a holistic framework for the development of next-generation hardware and software solutions, including innovative lidar solutions and CMOS imaging technologies. Project partners will leverage machine learning perception, delivering high-value, customized solutions across industry sectors. By aligning high-performance photonics with adaptive, application-specific analytics, RETINA seeks to deliver agile and efficient sensing solutions tailored to high-value industrial needs. This initiative represents a strategic step toward redefining how photonics and computation converge to shape the future of sensing.
Key Technologies: Detection and ranging, single photon detection, optical biosensors, agriphotonics, AI/ML, integrated sensors, CMOS sensors, wearables, automotive sensors, SWIR and VNIR sensors, INGaAs detectors, quantum dots, PICs-based lidar
Laser Safety: Laser Removal and Disposal
Within the Z136 Laser Standard series, only "Z136.1 — Safe Use of Laser" and "Z136.8 — Laser Safety in Research, Development and Testing" address the topic of safe and/or proper disposal of laser devices and sources. While the standards provide for four options, the realities that face an end-user, especially a buyer, often fail to align perfectly with the scenarios outlines in the standards. Indeed, the best solution for laser removal and disposal often depends on the type of laser, and its use history. Laser Safety Officer and Photonics Spectra columnist Ken Barat identifies best-practices for laser removal, and discusses strategies that users can adopt to determine the best path forward when it becomes time to remove, upgrade, or change laser equipment. Considerations for both standalone lasers and system-embedded equipment are examined.
Key Technologies: Laser safety, laser handling, laser purchasing.