The wave front sensing is to measure the amplitude and phase of the incoming light field at the same time.
Traditional wave front sensors like Shack
Hart wave front sensor (SHWFS)
Subject to the fundamental trade-off between spatial resolution and phase estimation, only a resolution of several thousand pixels can be obtained.
In order to break this trade-off, we propose a new calculationimaging-
Based on technology, that is, high-resolution wave front image sensor (WISH).
We replace the microlens array in SHWFS with a spatial light modulator (SLM)
And use the computing phase-
Pre-wave recovery algorithm.
This wave front sensor can be over 10-
Pixel resolution with fine phase estimation.
As far as we know, this resolution is one order of magnitude higher than the current non-interference wave front sensor.
To demonstrate the capabilities of WISH, we propose three applications covering a wide range of spatial scales.
First, we produce diffraction.
Long-term limited reconstruction
By Will desire and big-aperture, low-
Excellent Fresnel lens.
Second, we showed high.
The resolution image of the object that is obscured by scattering.
Third, we show that WISH can be used as a microscope without objective lenses.
Our research shows that the design principle of WISH combines the light modulator with the calculation algorithm to perceive the high
In the field of resolution optics, the ability of many existing applications has been improved, while revealing new application areas that have never been explored so far.
The behavior of light is like a wave, which can be characterized by its amplitude and phase.
However, current imaging sensors such as complementary metal oxide semiconductors (CMOS)
The sensor completely loses the phase information, limits the design of the traditional imaging system, and can only map all the information to the amplitude of the input field.
This kind of mapping is not always feasible and can cause many limitations.
In contrast, the goal of the wave front sensing is to simultaneously measure the amplitude and phase of the incoming light field.
The combination of these two kinds of information makes it possible to retrieve the light field in any plane, which provides greater freedom and greater flexibility for the design of the imaging system.
The importance of this technology has been demonstrated in the microscope, far
Field imaging, representation of optical elements by scattering media imaging.
Traditional wave front sensors are divided into two groups.
The first group is based on geometric optics. Shack-
Hart wave front sensor (SHWFS)
Is the most commonly used geometric design, it builds a lens array in front of the CMOS sensor.
Each lens provides measurements of the average phase slope (
In the lens area)
Based on the position of the focus on the sensor.
In order to achieve high phase accuracy, many pixels are required for each lens to locate spots precisely.
Therefore, although the CMOS sensor has millions of pixels, the spatial resolution of the complex field under test is very low.
Currently, commercial shwss offers up to 73 × 45 measurement points, which is useful for estimating only smooth phase profiles such as air turbulence.
The second group was designed based on diffraction optics.
The phase information is encoded into the interference stripe by introducing a reference beam.
However, these interference measurement systems have the following two limitations :(a)
Due to the increase in optical complexity, the system is large in size, heavy in weight, and (b)
The system is highly sensitive to the decimeter
Vibration of scale.
Can we overcome these limitations and design a non-interference, highresolution (multimegapixel)system?
Our main insight is to leverage the field of computational imaging, which provides an elegant framework for co-designing advanced computational algorithms and optical systems to develop new solutions for traditional imaging technologies.
This joint design approach overcomes many other constraints that are considered fundamental.
For example, super-resolution microscopy such as PALM and STORM have achieved subdiffraction-
By switching the light to high-
Accurate positioning algorithm.
Space provided by Fourier ptychography
Bandwidth products using LED array microscopy with phase
Search algorithm. Non-line-of-
Visual imaging enables people to look around with timeof-
Algorithm for flight setup and 3D reconstruction.
We recognize that traditional wave front sensors have problems with low spatial resolution and/or large vibration.
The sensitivity of the phase is measured directly.
Our proposed method avoids these shortcomings by combining optical modulation and computational optimization.
Specifically, we use two cuts.
Edge technology.
First, the current high
High performance CMOS technology
High resolution, highframe-
Rate image sensor and spatial light modulator (SLMs).
Latest Progress in Phase II
Retrieval algorithms and computing capabilities enable us to solve large
Optimization of scale.
By combining these two technological advances, we can create
Resolution intensity measurement and indirect phase recovery using phase-
Search algorithm.
Our approach was inspired by the recent efforts of various research groups to capture computational pre-wave measurements using SLM's sequence.
However, there are two limitations to the current technology, and our goal is to solve them directly.
First, the spatial resolution of the obtained wave front is limited.
Secondly, because the acquisition speed is not optimized enough, the sensor can not image the dynamic scene.
On the other hand, although the existing single
High frame with wave front sensor
Rate records, which are often dependent on assumptions such as thinning, and severely limit the applicability of these systems to general-purpose applications.
This paper introduces a high-resolution wave front imaging sensor (WISH)
, Which provides multi-pixel resolution, high frame rate, and robustness to vibration (Fig. ).
The WISH is made up of SLM, CMOS sensors and processors.
WISH imaging works by first modulation the light field with multiple random SLM modes and capturing the corresponding intensity
Measurements are made using only CMOS sensors.
Then, the acquired data is processed using the computing phase
Retrieval algorithm, which estimates complex light field events on SLM.
The spatial resolution of the recovery field is greater than 10 pixels.
Compared with the traditional SHFWS, there is an increase of more than 1000 in spatial resolution.
Compared with the recent design of other wave front sensors, WISH has achieved more than 10 times the spatial resolution.
While it takes multiple shots to recover a complex field, WISH can record dynamic scenes at a frame rate of up to 10 hz.
Last but not least, because the design is a reference-
WISH is robust to ambient noise and motion, which broadens the areas of application where the technology can be integrated.