Confocal microscopy features a good sectioning capability, which makes it essential for high-resolution 3D biological imaging. However, a tightly focused excitation beam inevitably leads to irreversible photodamage to live specimens, such as photobleaching and phototoxicity, and point-by-point scanning mechanism hampers its applications in fast volumetric imaging. As an alternative approach, selective plane illumination microscopy has shown outstanding performance in long-term imaging of embryonic development and neuronal activities attributed to its capabilities of intrinsic sectioning, gentle excitation and fast imaging. One drawback of SPIM is that the arrangement of two closely placed objectives greatly restricts the geometry of sample holders and the available numerical aperture (NA) for effective fluorescence collection. Here, we propose a highly-inclined plane illumination with a single high NA objective using for both excitation and detection. Unlike the requirement of two relay objective units in remote focusing imaging, an adaptive optical device serving as a flexible wavefront modulator compensates the systematical aberrations induced by optical components and effectively extended the imaging depth by generating an elongated point spread function (PSF). Our technique is applicable to single-molecule tracking and super-resolution imaging in live cells. Moreover, the adaptive optics can be replaced with a transmitted phase mask to enhance the effective fluorescent collection and simplify the system alignment effort.
A new scheme for ultrasensitive laser gyroscopes that utilizes the physics of exceptional points will be presented. By exploiting the properties of such non-Hermitian degeneracies, we show that the rotation-induced frequency splitting becomes proportional to the square root of the gyration speed (√𝛀)- thus enhancing the sensitivity to low angular rotations by orders of magnitudes. In addition, at its maximum sensitivity limit, the measurable spectral splitting is independent of the radius of the rings involved. Our work paves the way towards a new class of ultrasensitive miniature ring laser gyroscopes on chip.