All-reflective freeform microscope objective for ultra-broadband microscopy.

Conventional refractive microscope objective lenses have limited applicability to a range of imaging modalities due to the dispersive nature of their optical elements. Designing a conventional refractive microscope objective that provides well-corrected imaging over a broad spectral range can be challenging, if not impossible. In contrast, reflective optics are inherently achromatic, so a system composed entirely of reflective elements is free from chromatic aberrations and, as a result, can image over an ultra-wide spectral range with perfect color correction.

Vibrational imaging of metabolites for improved microbial cell strains.

Significance: Biomanufacturing utilizes modified microbial systems to sustainably produce commercially important biomolecules for use in agricultural, energy, food, material, and pharmaceutical industries. However, technological challenges related to non-destructive and high-throughput metabolite screening need to be addressed to fully unlock the potential of synthetic biology and sustainable biomanufacturing.

Aim: This perspective outlines current analytical screening tools used in industrial cell strain development programs and introduces label-free vibrational spectro-microscopy as an alternative contrast mechanism.

Infrared chemical imaging through non-degenerate two-photon absorption in silicon-based cameras.

Chemical imaging based on mid-infrared (MIR) spectroscopic contrast is an important technique with a myriad of applications, including biomedical imaging and environmental monitoring. Current MIR cameras, however, lack performance and are much less affordable than mature Si-based devices, which operate in the visible and near-infrared regions. Here, we demonstrate fast MIR chemical imaging through non-degenerate two-photon absorption (NTA) in a standard Si-based charge-coupled device (CCD).

High-resolution infrared imaging of biological samples with third-order sum-frequency generation microscopy.

We studied the use of vibrationally resonant, third-order sum-frequency generation (TSFG) for imaging of biological samples. We found that laser-scanning TSFG provides vibrationally sensitive imaging capabilities of lipid droplets and structures in sectioned tissue samples. Although the contrast is based on the infrared-activity of molecular modes, TSFG images exhibit a high lateral resolution of 0.

Hyperspectral imaging with laser-scanning sum-frequency generation microscopy.

Vibrationally sensitive sum-frequency generation (SFG) microscopy is a chemically selective imaging technique sensitive to non-centrosymmetric molecular arrangements in biological samples. The routine use of SFG microscopy has been hampered by the difficulty of integrating the required mid-infrared excitation light into a conventional, laser-scanning nonlinear optical (NLO) microscope. In this work, we describe minor modifications to a regular laser-scanning microscope to accommodate SFG microscopy as an imaging modality.