Spectroscopy in Forensics Spectroscopy continues to evolve in support of criminal forensics. As a result, law enforcement and crime labs are gaining faster, safer, and more sensitive tools for analyzing substances such as narcotics and biological evidence. Spectrometers are also becoming more portable, allowing forensic investigations to travel to the crime scene rather than the other way around. Hank Hogan speaks to instrument-makers, academics, and investigators to learn how advances in Raman and LIBS spectroscopy are changing the practice and efficacy of forensic investigation. Key Technologies: Raman spectroscopy (including handheld systems), laser-induced breakdown spectroscopy, Surface enhanced Raman spectroscopy Aspheres Asphericon's Ulrike Fuchs writes about the implicit challenges when tolerancing aspheres, which increasingly are manufactured in large batches. The broader use of asphere elements in optical assemblies has made a notable impact on the work of optical designers in defining system tolerances and requires a deeper understanding of the processes underlying production. Maintaining tolerances is important to maintain repeatability in system performance outcomes and therefore directly involved in optical system reliability. Key Technologies: aspheres, optical design, optical manufacturing Photon Counting Single-photon counting has become an important enabler for applications ranging from fluorescence lifetime measurements, to flow cytometry, to environmental monitoring for outdoors and in semiconductor cleanrooms. The technology is now well-positioned to further enable or enhance applications in lidar, quantum cryptography, quantum sensing, and other emerging fields. Excelitas's Richard Simmons of Excelitas will examine the science behind these applications and explain how single-photon counting will continue to be instrumental in the present and future technologies. Key Technologies: photodetectors, single-photon avalanche photodiodes (SPAD) Laser Beam Control High-power multimode lasers have long been used to cut metals, but they are not well-suited for precision material processing applications, such as the welding of brittle or porous materials, or of dissimilar or asymmetric parts. Fiber lasers, in contrast, offer long focal lengths more suitable for precision material processing. And with the advent of dynamic beam lasers (DBL) based on optical phased arrays (OPA), fiber lasers are now capable of delivering up to 100 kW of power with the precision control that multimode lasers lack. Civan's Ami Spira will look at new DBL developments that not only enhance control over beam shape but shape sequence, shape frequency, and focal depth. He will further detail how these parameters allow for unprecedented control of laser welding processes by controlling ablation and melt in ways that meet or exceed throughput and quality parameters for older technologies, such as brazing alloyed parts. Key Technologies: fiber lasers, laser welding, beam shaping, beam control, optical phase array Quantum Cascade Lasers Quantum cascade lasers (QCLs) have evolved from packaged lasers to a predominant source of coherent mid-infrared light targeting spectroscopic applications in defense, medical, and biopharma research. They continue to evolve into higher-power applications where ruggedness and compactness are essential. The rapid tempo of QCL advances and the rate of their adoption makes it difficult to know where to step into the topic. So, DRS Daylight Solutions' Bill Chapman provides a back to basics primer on the technology to provide context for his survey of the latest applications. Key Technologies: quantum cascade lasers, tetrahertz spectroscopy, microscopy