We describe a class of diffractive optical elements intended for use in holographic optical trapping systems that project ring-like optical traps. Unlike optical vortex traps, which carry orbital angular momentum, these ring-like traps implement a force-free one-dimensional potential energy well for micrometer scale objects. Also unlike most optical vortices or ring-like Bessel beams, these rin...

A reduced spatial and temporal coherence light from a halogen lamp is used to copy holographic optical elements, and a maximum diffraction efficiency of 80% is achieved.

BACKGROUND Advanced light microscopy offers sensitive and non-invasive means to image neural activity and to control signaling with photolysable molecules and, recently, light-gated channels. These approaches require precise and yet flexible light excitation patterns. For synchronous stimulation of subsets of cells, they also require large excitation areas with millisecond and micrometric resol...

The analysis of a slitless volume holographic spectrometer is presented in detail. The spectrometer is based on a spherical beam volume hologram followed by a Fourier-transforming lens and a CCD. It is shown that the spectrometer is not sensitive to the incident angle of the input beam for the practical range of applications. A holographic spectrometer based on the conventional implementation i...

Although the basic idea may be traced back to the earlier X-ray diffraction studies of Sir W. L. Bragg, the holographic method as we know it was invented by D. Gabor in 1948 as a two-step lensless imaging technique to enhance the resolution of electron microscopy, for which he received the 1971 Nobel Prize in physics. The distinctive feature of holography is the recording of the object phase va...

Single-beam optical gradient force traps created by focusing helical modes of light are known as optical vortices. Modulating the helical pitch of such a mode's wave front yields a new class of optical traps whose dynamically reconfigurable intensity distributions provide new opportunities for controlling motion in mesoscopic systems. An implementation of modulated optical vortices based on the...

Toroidal or cylindrical holographic gratings may be aplanetic at one wavelength in the XUV. Imaging of expanding plasmas may then be used for optical diagnostics of hot plasmas.