Abstract: Exemplary systems, methods, and devices are provided for measuring a force. Thus, the exemplary systems, methods, and devices can provide a remote optical sensor configured to measure force within the nanonewton range. The remote optical sensor can use avalanching nanoparticles to measure the force in that nanonewton range, where the brightness of the avalanching nanoparticles can be correlated to the applied force.

Abstract: A photo-switchable nanocrystal can be provided which can include solely one or more inorganic elements. Further, a method for synthesizing photo-switchable nanocrystal can be provided which can utilize solely inorganic elements. For example, the fully inorganic element(s) can comprise lanthanide ion (Ln3+)-based phosphors. Further, the nanocrystal can be photostable and/or does not photodegrade with light excitation cycles.

Abstract: Phonon engineered, lanthanide doped upconverting nanoparticles with very low phonon energies and tunable methods of synthesis that adjust OA:OM ratio and reaction temperature are provided. Low phonon energy KPb2X5 (X=Cl, Br) upconverting nanoparticles, both doped and undoped, exhibit dramatically suppressed multiphonon relaxation, enhancing upconversion emission from higher lanthanide excited states and enabling room temperature observation of avalanche like upconversion by Nd3+ ions. Intrinsic optical bistability (IOB) of the materials can provide bit level functionality to all optical computing. The IOB of Nd3+ doped nanocrystals, which are either bright or dark at the same excitation power based on power history, illustrate the functionality. High contrast switching and IOB are enabled via the photon avalanche process, which sustains population inversion between the ground and the first excited 4fN states of Nd3+ ions.

Abstract: Exemplary nanoparticle and method for inducing photon avalanching using a nanoparticle can be provided. The nanoparticle can include, for example, at least 99% thulium doped nanocrystals of the nanoparticle. The nanoparticle can be composed of solely thulium. An atomic concentration of the thulium can be at least 8%. A near infrared excitation wavelength of the nanocrystals can be greater than about 1064 nm. The near infrared excitation wavelength can be between about 1400 nm to about 1490 nm. A passivated shell(s) can be included which can surround the nanocrystals.

Abstract: Exemplary nanoparticle and method for inducing photon avalanching using a nanoparticle can be provided. The nanoparticle can include, for example, at least 99% thulium doped nanocrystals of the nanoparticle. The nanoparticle can be composed of solely thulium. An atomic concentration of the thulium can be at least 8%. A near infrared excitation wavelength of the nanocrystals can be greater than about 1064 nm. The near infrared excitation wavelength can be between about 1400 nm to about 1490 nm. A passivated shell(s) can be included which can surround the nanocrystals.