Introduction.- Practical Quantum Measurements.- Introductory Theory of Optical Tweezers.- The Total Information Carried by the Light.- The Quantum Noise Limit for a Specific Measurement.- Characterizing Quadrant Detection.- Interferometer Enhanced Particle Tracking.- Homodyne Based Particle Tracking.- Lock-In Particle Tracking.- Selective Measurement by Optimized Dark-Field Illumination Angle.- Technical Constraints on Sensitivity.- Surpassing the Quantum Limit.- Biological Measurement Beyond the Quantum Limit.- Sub diffraction-Limited Quantum Imaging of a Living Cell.- Further Extensions.- Summary and Conclusion.

 This thesis reports on the development of the first quantum enhanced microscope, and on its applications in biological microscopy. The first quantum particle-tracking microscope, described in detail here, represents a pioneering advance in quantum microscopy, which is shown to be a powerful and relevant technique for future applications in science and medicine.  The microscope is used to perform the first quantum-enhanced biological measurements -- a central and long-standing goal in the field of quantum measurement. Subdiffraction-limited quantum imaging is achieved, also for the first time, with a scanning probe imaging configuration allowing 10-nanometer resolution. 

Nominated as an outstanding Ph.D. thesis by the University of Queensland, Australia Describes the design and construction of the first quantum-enhanced microscope Reports on the first biophysics experiments to break the quantum shot-noise limit Provides insight into the significance and potential of quantum measurements in biology Includes supplementary material: sn.pub/extras