Esther Lin

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on the atlas · 33

highlights · 271

Ideal bandpass filter
Foundations of signal processing
Lagrange interpolation
vandemonde.pdf
circular prolate spheroidal wave functions (CPSWFs) as a basis set on the FoV
Optimising superoscillatory spots for far-fieldsuper-resolution imaging
the solution with optimal energy yield may not be optimal for optical imaging
Optimising superoscillatory spots for far-fieldsuper-resolution imaging
The specifications of surface relief gratings such as shape, slant angle, and aspect ratio are fine-tuned using rigorous simulations to achieve spatial and angular uniformity at the eyebox domain
Waveguide holography for 3D augmented reality glasses | Nature Communications
This effectively increases the numerical aperture of the display system and improve the resolution
Waveguide holography for 3D augmented reality glasses | Nature Communications
With the knowledge of light interaction in the waveguide, the phase discontinuities caused by beam clippings can be stitched to achieve smooth phase in the eyebox
Waveguide holography for 3D augmented reality glasses | Nature Communications
phase discontinuities caused by beam clippings can be stitched to achieve smooth phase in the eyebox
Waveguide holography for 3D augmented reality glasses | Nature Communications
ideal lossless waveguide
Waveguide holography for 3D augmented reality glasses | Nature Communications
Full 3D results captured with temporally multiplexed CG
Waveguide holography for 3D augmented reality glasses | Nature Communications
Display results of the compact prototype are presented in Fig. 5b
Waveguide holography for 3D augmented reality glasses | Nature Communications
When finite depth holograms are displayed, the images suffer severely from ghost noise and aberration created by duplicated pupils without our method
Waveguide holography for 3D augmented reality glasses | Nature Communications
replaced with a generic wave propagation function that is agnostic to the waveguide
Waveguide holography for 3D augmented reality glasses | Nature Communications
Wavefront cameras can avoid aberration from the camera lens or alignment error because numerical propagation replaces a physical aperture and camera lens
Waveguide holography for 3D augmented reality glasses | Nature Communications
3D printed entrance pupil mask with the exact size and position of the targeted ROI and capture the image directly
Waveguide holography for 3D augmented reality glasses | Nature Communications
Once the model training is finished, the CGH can be calculated by adding a numerical propagation at the end of the model pipeline with parameterized input phase of the SLM as illustrated in 2
Waveguide holography for 3D augmented reality glasses | Nature Communications
multi-channel complex apertures Q (top)
Waveguide holography for 3D augmented reality glasses | Nature Communications
This is a significant difference from conventional camera-in-the-loop calibration methods, which were not practical for calibrating all the possible pupil locations and sizes separately.
Waveguide holography for 3D augmented reality glasses | Nature Communications
By measuring the intensity only, it is difficult to infer the waveguide kernels and complex apertures in the model as the useful information is buried in the noisy interference pattern. With the wavefront camera, the access to phase information could successfully retrieve the coherent light interaction in the waveguide.
Waveguide holography for 3D augmented reality glasses | Nature Communications
The physical propagation includes free space propagation, as well as 3D tilt and a homography changes from the alignment mismatch and aberration
Waveguide holography for 3D augmented reality glasses | Nature Communications
multi-channel convolution model with complex apertures to handle the spatially variant nature of the system
Waveguide holography for 3D augmented reality glasses | Nature Communications
all the complicated interactions can be simplified as a single convolution operation
Waveguide holography for 3D augmented reality glasses | Nature Communications
The LSI assumption enables key advantages to model the waveguide system in terms of Fourier optics regimes.
Waveguide holography for 3D augmented reality glasses | Nature Communications
the first order diffraction at the gratings
Waveguide holography for 3D augmented reality glasses | Nature Communications
The luminance of ambient background for aviators at altitude such as sun-lit snow or clouds may be up to approximately 10,000 fL.
Head-Mounted Display Systems
Regarding brightness, some of the most challenging environments are outdoor and surgical environments. In all cases, the brightness of presented images must be at least that of the average environment brightness
Head-Mounted Display Systems
The challenge in developing microdisplays for HMDs is providing high resolution on a reasonably sized yet not too large substrate (i.e., 0.6–1.3 in.), and high uniform luminance, which is measured either in foot-Lambert (fL) or Candelas per square meter (cd = m 2 ) (i.e., 1 cd = m 2 equals to 0.29 fL).
Head-Mounted Display Systems
HMD is composed of a modulated light source with drive electronics viewed through an optical system
Head-Mounted Display Systems
owever, current magnifier designs typically require multiple optical elements to minimize aberrations, leading to bulky eyewear with limited fields of view that have, to date, prohibited widespread consumer adoption
Near-Eye Light Field Displays
synthesizing an enlarged image of a miniaturized display, appearing to be located within the viewer’s natural accommodation range
Near-Eye Light Field Displays
fundamental problem: the unaided human eye cannot accommodate (focus) on objects placed in close proximity (see Figure 1)
Near-Eye Light Field Displays
Human corrective feedback is a crucial form of guidance to enable such generalization
droc
ommercial microscopes with infinity-corrected objectives can almost always can be modeled by considering the tube lens as paraxial
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
s a rule of thumb, non-paraxial effects only become significant when the numerical aperture of a lens exceeds 0.
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
A lens can be considered paraxial if the angle α between the optical axis of the lens and the marginal ray is small enough that sin α ≈ α
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
Geometry first, symmetry second, basis third
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
econd, real imaging systems miss the physical limit by a factor of 1 / sin α , which highlights the importance of interfering waves from a wide range of angle
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
real irradiance spots sizes do not saturate the physical limit
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
we can never hope to recover information about the sample in object volumes smaller than [ λ/ (2 n )] 3 without prior information
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
herefore, the minimum irradiance spot size is approximately λ/ (2 n )
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
maximum spatial frequency of the irradiance pattern is 2 n/λ
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
hase-modifying elements are available, so we can use interference to shape the point-spread function into a spot that is much narrower than Eq. (1.2).
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
The breadth of the point-spread function indicates how much information about the emitter’s position is encoded into our measurements, and in this case the point- spread function has a broad 1 /r 2 dependence
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
Readers familiar with quantum mechanics will recognize that the scalar fields in Eq. (1.1) play the role of the wave function, the irradiance in Eq. (1.2) plays the role of an unnormalized detection probability, and photon measurements consist of discrete events that “collapse the wavefunction”.
Spatio-Angular Flourescent Microscopy -- Talon Chandler Dissertation
angular spectrum method
Optimizing image quality for holographic near-eye displays with Michelson Holography
does not require us to explicitly model the SLM pixel structure or the undiffracted light
Optimizing image quality for holographic near-eye displays with Michelson Holography
captures the coherent superposition of all diffracted and undiffracted light of the display and backpropagates the error w.r.t. a target image into both SLM patterns simultaneously
Optimizing image quality for holographic near-eye displays with Michelson Holography
the undiffracted light can contribute to forming the target image rather than creating speckle and other artifacts
Optimizing image quality for holographic near-eye displays with Michelson Holography
core idea of MH is to destructively interfere the diffracted light of one SLM with the undiffracted light of the other
Optimizing image quality for holographic near-eye displays with Michelson Holography
camera-in-the-loop (citl) holography techniques have been described that can partially compensate the undiffracted light of an SLM using its diffracted component without having to explicitly model all of these terms
Optimizing image quality for holographic near-eye displays with Michelson Holography