Incoherent microscopy and spectroscopy of biological assemblies

Incoherence in optical microscopy and spectroscopic analyses is typically viewed as an undesired artifact, resulting in loss of information relative to coherently generated and propagated signal. However, partial incoherence is common in nonlinear optical microscopy from inherent spatial heterogeneity over length scales comparable in detection wavelength within the field of view. Intriguingly, incoherence opens access to new observables not present in coherent spectroscopy and microscopy with unique dependence on macromolecular structure and orientation. In one prominent example, we demonstrate through theory and experiment the emergence of new chiral-specific and orientation-selective phenomena exclusively arising upon the loss of coherence within the spectroscopic observables.