better spacing

README.md

@@ -83,7 +83,7 @@ Other optimization based methods leverage gradient descent or non-convex optimiz
 - [Accommodative Holography: Improving Accommodation Response for Perceptually Realistic Holographic Displays](https://drive.google.com/drive/folders/1K0DfdG75kcz_xU6BF9PDwzevhp1t_UmO) (*Kim et al. 2022 | SIGGRAPH, ACM*) analyzed the user accomodation performance when using different CGH methods and proposed a novel constrast ratio-based regularization loss that promotes better accomodation cues.
 - [Metameric Varifocal Holograms](https://github.com/complight/metameric_holography) (*Walton et al. 2022 | VR, IEEE*) proposed a foveated graphics-inspired, gaze-contingent loss function that can be easily integrated into CGH optimization loops.
 - [Hogel-free Holography](https://dl.acm.org/doi/pdf/10.1145/3516428) (*Chakravarthula et al. 2022 | SIGGRAPH, ACM*)
-- [Optimization of computer-generated holograms featuring phase randomness control](https://opg.optica.org/ol/fulltext.cfm?uri=ol-46-19-4769&id=459763)(*Yoo et al. | Optics Express, Optica*) leveraged a learned DPAC encoding optimized using gradinet descent to promote phase randomness, which in turn increases the space-bandwidth product of the display system.
+- [Optimization of computer-generated holograms featuring phase randomness control](https://opg.optica.org/ol/fulltext.cfm?uri=ol-46-19-4769&id=459763) (*Yoo et al. | Optics Express, Optica*) leveraged a learned DPAC encoding optimized using gradinet descent to promote phase randomness, which in turn increases the space-bandwidth product of the display system.
 - [Multi-depth hologram generation using stochastic gradient descent algorithm with complex loss function](https://opg.optica.org/oe/fulltext.cfm?uri=oe-29-10-15089&id=450644) (*Chen et al. 2021 | Optics Express, Optica*)
 - [Realistic Defocus Blur for Multiplane Computer-Generated Holography](https://arxiv.org/abs/2205.07030) (*Kavaklı et al. 2021*) proposed a novel loss function aimed to synthesize high quality defocus blur, and can be intergated in various iterative (GS, gradient-descent) and non-iterative (double phase encoding) methods. 
 - [Wirtinger Holography for Near-Eye Displays](https://www.cs.princeton.edu/~fheide/wirtingerholography) (*Chakravarthula et al. 2019 | SIGGRAPH Asia, ACM*) optimizes the phase-only SLM pattern using closed-form Wirtinger complex derivatives in gradient descent.
@@ -99,7 +99,7 @@ There are often mismatches between a ideal wave propagation model (e.g. ASM) wit
 - [Time-multiplexed Neural Holography: A Flexible Framework for Holographic Near-eye Displays with Fast Heavily-quantized Spatial Light Modulators](https://www.computationalimaging.org/publications/time-multiplexed-neural-holography/) (*Choi et al. 2022 | SIGGRAPH, ACM*) leveraged time-multiplexed quantized SLM patterns to synthesize high quality defocus blur. 
 - [Learned Hardware-in-the-loop Phase Retrieval for Holographic Near-Eye Displays](https://light.princeton.edu/publication/hil-holography/) (*Chakravarthula et al. 2020 | SIGGGRAPH Asia, ACM*) uses CITL to learn an aberration approximator that models the residual between holograms generated from ideal wave propagation (i.e. ASM) and real-world wave propagation models. An adversarial loss is used in addition to reconstruction loss to optimize the synthesized holograms.
 
-Instead of using a predetermined convolution kernel to compute wave propagation (i.e. the angular spectrum method), [Learned holographic light transport](https://arxiv.org/pdf/2108.08253.pdf) (*Kavaklı et al. 2021 | Applied Optics, Optica*) learns the wave propagation convolution kernel directly from images captured by a physical holographic display.
+Instead of using a predetermined convolution kernel to compute wave propagation (i.e. the angular spectrum method), [Learned holographic light transport](https://opg.optica.org/ao/abstract.cfm?uri=ao-61-5-b50) (*Kavaklı et al. 2021 | Applied Optics, Optica*) learns the wave propagation convolution kernel directly from images captured by a physical holographic display.
 
 ### Learned Hologram Synthesis Methods
 These works often assume a naive wave propagation model (i.e. the angular spectrum method (ASM)), and directly regresses complex holograms using novel CNN architectures:
@@ -116,8 +116,8 @@ These works often assume a naive wave propagation model (i.e. the angular spectr
 ### Speckle Noise Reduction
 Speckle noise is a result of interference among coherent waves, which is often present in holographic images since holographic displays use coherent laser sources. Methods for reducing speckle noise can roughly be catergorized into the following:
 #### Time-averaging
-- [High‐contrast, speckle‐free, true 3D holography via binary CGH optimization](https://www.nature.com/articles/s41598-022-06405-2#Sec15)(*Lee et al. 2022 | Scientific Reports, Nature*) optimized random phase, amplitude only SLMs using gradient descent and time-averaged them to reduce speckle noise.
-- [DCGH: Dynamic Computer Generated Holography for Speckle-Free, High Fidelity 3D Displays](https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9417658)(*Curtis et al. 2021 | IEEE, VR*) simultaneously optimizes multiple binary, amplitude only SLMs in a modified Gerchberg-Saxton (GS) algorithm and time-averages them to reduce speckle noise.
+- [High‐contrast, speckle‐free, true 3D holography via binary CGH optimization](https://www.nature.com/articles/s41598-022-06405-2#Sec15) (*Lee et al. 2022 | Scientific Reports, Nature*) optimized random phase, amplitude only SLMs using gradient descent and time-averaged them to reduce speckle noise.
+- [DCGH: Dynamic Computer Generated Holography for Speckle-Free, High Fidelity 3D Displays](https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9417658) (*Curtis et al. 2021 | IEEE, VR*) simultaneously optimizes multiple binary, amplitude only SLMs in a modified Gerchberg-Saxton (GS) algorithm and time-averages them to reduce speckle noise.
 #### Partially-coherent Light Sources
 - [Speckle-free holography with partially coherent light sources and camera-in-the-loop calibration](https://www.computationalimaging.org/publications/partiallycoherentholography/) (*Peng et al. 2021 | Science Advaces, Science*) uses partially coherent light sources (i.e. LED) and camera-in-the-loop optimization to reduce speckle noise.
 - [Light source optimization for partially coherent holographic displays with consideration of speckle contrast, resolution, and depth of field](https://www.nature.com/articles/s41598-020-75947-0) (*Lee et al. 2020 | Scientific Reports, Nature*)
@@ -142,7 +142,7 @@ Bulky headsets hamper the development of AR/VR. **Reducing the size** of hologra
 - [Holographic Glasses for Virtual Reality](https://research.nvidia.com/publication/2022-08_holographic-glasses-virtual-reality) (*Kim et al. 2022 | SIGGRAPH, ACM*) presents a holographic display system with eyeglasses-like form factor. An optical stack of 2.5mm is achieved by combining pupil-replicating waveguide, SLMs, and geometric phase lenses.
 - [Holographic pancake optics for thin and lightweight optical see-through augmented reality](https://opg.optica.org/oe/fulltext.cfm?uri=oe-29-22-35206&id=460506) (*Cakmakci et al. 2021 | Optics Express, Optica*)
 - [Holographic Optics for Thin and Lightweight Virtual Reality](https://research.facebook.com/publications/holographic-optics-for-thin-and-lightweight-virtual-reality/) (*Maimone et al. 2021 | SIGGRAPH, ACM*)
-- [Unfiltered holography: optimizing high diffraction orders without optical filtering for compact holographic displays](https://opg.optica.org/ol/fulltext.cfm?uri=ol-46-23-5822&id=464968)(*Gopakumar et al. 2021 | Optics Letters, Optica*) incorporated higher diffraction orders into the CGH optimization procedure to remove the 4f filtering system often used in holographic displays, thus reducing the display form factor.
+- [Unfiltered holography: optimizing high diffraction orders without optical filtering for compact holographic displays](https://opg.optica.org/ol/fulltext.cfm?uri=ol-46-23-5822&id=464968) (*Gopakumar et al. 2021 | Optics Letters, Optica*) incorporated higher diffraction orders into the CGH optimization procedure to remove the 4f filtering system often used in holographic displays, thus reducing the display form factor.
 
 ### Compression
 **CGH compression** is also important for deploying holography technology on edge devices: