Complex Hologram Calculation With Discrete Amplitude-Phase Levels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing holographic projection technologies struggle to achieve high-quality reconstructions due to limitations in amplitude and phase modulation, leading to noise and inefficiencies in calculating and displaying complex holograms.
Innovation Solution
A holographic projector with individually-addressable liquid crystal pixels that modulate both amplitude and phase, utilizing a range of complex modulation levels spanning at least 3π/2, including a zero amplitude and zero phase level, to minimize noise and improve reconstruction quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional amplitude-only or phase-only modulation is used, then device complexity is reduced, but manufacturing precision of holographic reconstruction deteriorates due to inability to modulate both amplitude and phase
Solution Approach 1:
The patent combines amplitude modulation and phase modulation capabilities into a single liquid crystal pixel structure. The liquid crystal layer is configured to simultaneously control both the amplitude and phase of incident light, eliminating the need for separate amplitude and phase modulators and achieving full complex modulation in one device.
Solution Approach 2:
The liquid crystal pixel is designed to perform multiple functions: it acts as both an amplitude modulator and a phase modulator. By adjusting the liquid crystal orientation and optical path difference, the same pixel can independently control amplitude transmission and phase delay, providing universal complex modulation capability.
2Manufacturing precision
If continuous complex modulation is implemented, then manufacturing precision improves, but ease of operation deteriorates due to difficulty in controlling both amplitude and phase independently
Solution Approach 1:
The patent segments the complex modulation control into two independent controllable parameters: amplitude transmission (controlled by liquid crystal orientation angle) and phase delay (controlled by optical path difference). This segmentation allows independent adjustment of amplitude and phase without coupling, simplifying the control process while maintaining full complex modulation capability.
Solution Approach 2:
The patent changes the operational parameters of the liquid crystal by controlling its orientation angle and optical path difference. These parameter changes enable the liquid crystal to transition between different modulation states, achieving independent amplitude and phase control through well-defined physical parameters that can be precisely adjusted.
3Manufacturing precision
If noise reduction techniques are applied, then manufacturing precision improves, but productivity decreases due to increased computational iterations required
Solution Approach 1:
The patent extracts and eliminates the zero-order diffraction term, which is the primary source of noise in holographic reconstruction. By removing this unwanted component through appropriate optical filtering or computational subtraction, the noise is eliminated without requiring additional iterative calculations, thus maintaining both image clarity and computational efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables faster and higher-quality holographic reconstructions by constraining complex hologram data values to specific modulation levels, reducing noise and requiring fewer computational iterations, thus enhancing image clarity and efficiency.
Implementation Method 1
Each light-modulating pixel is a cell containing liquid crystal operable to modulate both amplitude and phase
Implementation Method 2
The complex modulation levels comprise phase modulation values which substantially span at least 3π/2, optionally 2π
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A method of calculating a hologram having an amplitude and a phase component. The method comprises (i) receiving an input image comprising a plurality of data values representing amplitude. The method then comprises (ii) assigning a random phase value to each data value of the plurality of data values to form a complex data set. The method then comprises (iii) performing an inverse Fourier transform of the complex data set. The method then comprises (iv) constraining each complex data value (X1, X2) of the transformed complex data set to one of a plurality of allowable complex data values (GL1-GL8), each comprising an amplitude modulation value and a phase modulation value, to form a hologram, wherein, the phase modulation values (GL1-GL7) of the plurality of allowable complex data values substantially span at least 3π/2 and at least one of the allowable complex data values has an amplitude modulation value of substantially zero (GL8) and a phase modulation value of substantially zero.