Instant Polarizing Microscope

Abstract

The polarized light microscope includes a light source configured to illuminate a sample and an image sensor configured to capture an image of the sample. The polarized light microscope further includes a first circular polarizer disposed between the light source and the sample. A mosaic birefringent mask is disposed between the sample and the image sensor. The polarized light microscope further includes a second polarizer disposed between the mask and the image sensor.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 306,604, filed February 4, 2022, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Polarized Light Microscopy (PLM) has been widely used for two centuries since the development of the first polarized light microscope in 1834 by Henry Talbot. PLM systems introduce contrast into samples that would otherwise be invisible if the sample contains birefringent molecules or structures. PLM microscopes generate a polarized probe beam and convert changes in the orientation and / or ellipticity of the polarized light introduced by the sample under investigation into changes in color and / or intensity, allowing geologists, physicists, chemists, biologists, and engineers to study birefringent samples. PLM microscopes were originally configured for the petrographic investigation of rock thin sections, but in recent years have found increasing importance in the fields of chemistry, ceramic technology, metallography, crime detection, military intelligence, biology, and medicine. Summary of the Invention

[0003] An exemplary polarized light microscope includes a light source configured to illuminate a sample and an image sensor configured to capture an image of the sample. The polarized light microscope further includes a first circular polarizer disposed between the light source and the sample. A mosaic birefringent mask is disposed between the sample and the image sensor. The polarized light microscope further includes a second polarizer disposed between the mask and the image sensor.

[0004] In one embodiment, the second polarizer and the mosaic birefringent mask are attached to the image sensor. In another embodiment, the second polarizer and the mosaic birefringent mask are arranged in a conjugate plane with the image sensor. The system may further include an objective lens arranged between the sample and the mosaic birefringent mask. In another embodiment, the second polarizer includes a circular polarizer. In one embodiment, the second polarizer includes a right-handed circular polarizer and the first polarizer includes a left-handed circular polarizer.

[0005] In one embodiment, a superpixel of the mosaic birefringent mask comprises a first square (or pixel), a second square (or pixel), a third square (or pixel), and a fourth square (or pixel) having a retardation range of 0 to 0.25λ. In one implementation of such an embodiment, the first square is not birefringent, and the second square, the third square, and the fourth square have equal retardation ranging from 0.01λ to 0.25λ. Furthermore, the second square has a slow axis orientation that is 0°, the third square has a slow axis orientation that is 60°, and the fourth square has a slow axis orientation that is 120°. Alternatively, the second square has a slow axis orientation that is 0°, the third square has a slow axis orientation that is 45°, and the fourth square has a slow axis orientation that is 90°. In another alternative configuration, the first square, the second square, the third square, and the fourth square have equal retardation in the range of 0.01λ to 0.25λ, and the first square has a slow axis orientation that is 0°, the second square has a slow axis orientation that is 45°, the third square has a slow axis orientation that is 90°, and the fourth square has a slow axis orientation that is 135°.

[0006] In one embodiment, the mosaic birefringent mask comprises two sets of superpixels. In another embodiment, the mosaic birefringent mask is fabricated by laser pulses directed into a quartz substrate. Alternatively, the mosaic birefringent mask may be formed by a nanostructured surface. The mosaic birefringent mask may also be composed of microtiles fabricated from a birefringent film.

[0007] An exemplary instant imaging full Stokes polarimeter includes a polarization image sensor including a mosaic polarization mask and an image sensor. The polarimeter further includes a mosaic birefringent mask proximate to the polarization image sensor. The mosaic birefringent mask includes a plurality of birefringent superpixels, each birefringent superpixel being formed from one or more non-birefringent pixels and one or more birefringent pixels. The polarimeter further includes a processor operatively coupled to the polarization image sensor. The processor is configured to process a plurality of intensity signals generated by the superpixels of the image sensor to determine Stokes parameters of an image captured by the image sensor.

[0008] In one embodiment, the polarizer comprises a mosaic polarizing mask comprising a plurality of polarizing superpixels, each polarizing superpixel comprising a plurality of micropolarizers. In another embodiment, the polarizer comprises a circular polarizer. In another embodiment, the mosaic birefringent mask is attached to one or more of the image sensor and the polarizer. In one embodiment, the mosaic birefringent mask comprises two sets of superpixels. In another embodiment, each birefringent superpixel comprises six pixels.

[0009] Other principal features and advantages of the present invention will become apparent to those skilled in the art upon review of the following drawings, detailed description, and appended claims. [Brief description of the drawings]

[0010] Exemplary embodiments of the invention are described below with reference to the accompanying drawings.

[0011] [Figure 1A] 1 illustrates a pattern of a first mosaic birefringent mask according to an exemplary embodiment. [Figure 1B] 1 shows an example of a basic group of four mosaic squares, which may be called a superpixel, according to an exemplary embodiment, where the hash marks indicate the retardance and slow axis orientations of the first mosaic birefringent mask. [Figure 2A] 13 illustrates a pattern of a second mosaic birefringent mask according to an example embodiment. [Figure 2B] 1 shows an example of a basic group of four mosaic squares, which may be called a superpixel, according to an exemplary embodiment, where the hash marks indicate the retardance and slow-axis orientations of the second mosaic birefringent mask. [Figure 3A] 13 illustrates a pattern of a third mosaic birefringent mask according to an exemplary embodiment. [Figure 3B] 13 illustrates an example of a basic group of four mosaic squares with colors indicating retardance and slow axis orientation of a third mosaic birefringent mask according to an exemplary embodiment. [Figure 4A] 13 illustrates a pattern of a fourth mosaic birefringent mask according to an exemplary embodiment. [Figure 4B] 13 illustrates an example of a basic group of four mosaic squares with colors indicating retardance and slow axis orientation of a fourth mosaic birefringent mask according to an exemplary embodiment. [Figure 5A] 1 illustrates an example of a first mosaic birefringent mask configuration implemented using two basic groups according to an exemplary embodiment. [Figure 5B]1 shows four variations of a basic group having four (2x2) mosaic squares according to an exemplary embodiment. [Figure 5C] 1 illustrates a basic group having 16 (4×4) mosaic squares according to an exemplary embodiment. [Figure 6] 1 shows an example of an instant polarized light microscope with a mosaic birefringent mask and a circular polarizer attached directly to an image sensor (photodiode array) according to an example embodiment. [Figure 7] 1 shows an example of an instantaneous polarizing microscope in which a mosaic birefringent mask and a circular polarizer are positioned in a conjugate plane with the image sensor (i.e., an intermediate image plane) according to an example embodiment. [Figure 8] FIG. 1 is a schematic diagram of an instant polarizing microscope with a reflected light path, according to an example embodiment. [Figure 9] 1 shows a mosaic birefringent mask written (nano-machined) inside a quartz substrate by laser pulses according to an example embodiment. [Figure 10] 1 illustrates an instantaneous polarizing microscope having a mosaic birefringent mask and a polarizing image sensor according to an example embodiment. [Figure 11] 1 illustrates a first mosaic birefringent mask pattern for full Stokes polarization parameter imaging according to an example embodiment. [Figure 12] 13 illustrates a pattern of a second mosaic birefringent mask for imaging full Stokes polarization parameters according to an example embodiment. [Figure 13]Fig. 13A shows a pattern of a third mosaic birefringent mask for imaging full Stokes polarization parameters according to an exemplary embodiment. Fig. 13B shows two superpixels of the mosaic birefringent mask according to an exemplary embodiment. Fig. 13C shows two sets of six signals generated by two superpixels of the mosaic birefringent mask according to an exemplary embodiment. [Figure 14] FIG. 1 illustrates a block diagram of a computing system for implementing a microscopy imaging system according to an exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Over the last 30 years, several schemes have been proposed to automate the measurement process of polarized light microscopy to more fully utilize its analytical power. These schemes have always included the use of a conventional compensator, which is either turned under computer control or replaced by electro-optical modulators such as Pockels cells, Faraday rotators, and liquid crystal variable retarders. Alternatively, some conventional systems split the imaging beam, take multiple images simultaneously, and analyze each for different polarization states. These schemes also include quantitative intensity measurements using electronic photodetectors such as photomultiplier tubes or digital cameras. More recently, quantitative instant polarized light microscopy (PLM) has become available that uses a charge-coupled device (CCD) chip equipped with a mosaic polarizing mask. These conventional PLMs use a four-frame algorithm with a linear polarization setting. However, this approach has an inherently low signal-to-noise ratio in scenarios involving measurements of weakly birefringent samples such as cell division spindles, collagen fibers, and nanofabricated structures of optical information carriers. Furthermore, conventional PLM can only reveal anisotropic structures with a limited range of orientations relative to the polarization axis of the microscope, and the use of conventional compensators is time-consuming for the measurement of optical anisotropies, such as birefringence.

[0013] We proposed an algorithm using an elliptically polarized setting and created two types of highly sensitive quantitative PLMs with single or dual liquid crystal polarization state generators. These PLMs, called LC-Polscope, simultaneously measure the birefringence microstructure over the entire field of view, for all birefringence axis orientations, with high sensitivity (e.g., birefringence retardation of 0.02 nm), high resolution (e.g., 0.2 μm), and short time interval (e.g., 1 s).

[0014] Described herein is an instant polarizing microscope that offers the same high sensitivity as the LC-Polscope. However, the instant polarizing microscope proposed here is free of artifacts caused by the movement of sample structures during image acquisition. The proposed microscope is also more robust and less expensive than existing systems because, in an exemplary embodiment, it does not utilize liquid crystal optics with electronic controllers. The proposed microscope can also be used in a wider spectral range and in significantly harsher environmental conditions than existing systems due to the absence of liquid crystal elements. The proposed microscope is well suited for mass production and widespread use in science, education, and industry. The proposed microscope is also user-friendly because it precludes recalibration caused by retardation drift of liquid crystal optics.

[0015] In an exemplary embodiment, the proposed instant polarized light microscope utilizes a birefringent assembly including a mosaic birefringent mask and a polarizer. The mosaic birefringent mask may comprise four adjacent circular polarizing filters in one embodiment. In another embodiment, the mosaic birefringent mask may comprise three adjacent circular polarizing filters and one circular polarizing filter. The inventors have proposed various basic configurations of the mosaic mask designed to work with a specific algorithm for the calculation of the two-dimensional retardance map. In the drawings (described below) showing the mosaic mask, one birefringent mosaic square corresponds to one pixel on the image sensor.

[0016] The proposed mosaic birefringent mask differs from conventional masks in several ways. For example, some polarization image sensors are created by a linear polarizer mosaic mask and a photodiode array. In such a mask, there are four pixels with a wire grid linear polarizer and transmission surfaces oriented at 0°, 45°, 90°, and 135°. As discussed in more detail below, the proposed mosaic birefringent mask differs from such conventional systems in configuration, retardation, and slow axis orientation.

[0017] The proposed mosaic birefringent mask can be fabricated in several ways: for example, the mask can be written (nanomachined) inside a quartz substrate by laser pulses, it can also be formed by a nanostructured surface, a patterned liquid crystal array, a patterned photonic crystal array, or it can consist of microtiles made from a birefringent film.

[0018] FIG. 1 illustrates the configuration of a first mosaic mask. Specifically, FIG. 1A illustrates a pattern of a first mosaic birefringent mask according to an exemplary embodiment. FIG. 1B illustrates an example of a basic group of four mosaic squares, which may be called a superpixel, according to an exemplary embodiment. In this figure, hash marks indicate the retardance and slow axis orientation of the first mosaic birefringent mask. In the figure, delta symbols indicate retardation and psi symbols indicate slow axis orientation. In the embodiment of FIG. 1, the empty / white squares of the mask are not birefringent and have a retardation of 0 nm. Squares with horizontal lines have a retardation of 20 nm (~0.03 λ) and a slow axis of 0°, squares with positively slanted lines have a retardation of 20 nm and a slow axis of 60°, and squares with negatively slanted lines have a retardation of 20 nm and a slow axis of 120°. The tessellated mask of FIG. 1 is designed to work with a new modified symmetric three-frame algorithm and additional extinction settings.

[0019] FIG. 2A shows a pattern of the second tessellated birefringent mask according to an exemplary embodiment. FIG. 2B shows an example of a basic group of four tessellated squares with colors indicating retardance and slow-axis orientation of the second tessellated birefringent mask according to an exemplary embodiment. The proposed second tessellated birefringent mask is designed to work with a symmetric four-frame algorithm. As shown, a superpixel of the mask comprises four pixels with retardation of 20 nm (~0.03 λ). The hatch pattern directions indicate the slow-axis orientations φ, which are 0°, 45°, 90°, and 135°.

[0020] FIG. 3A shows a pattern of the third mosaic birefringent mask according to an exemplary embodiment. FIG. 3B shows an example of a basic group of four mosaic squares with colors indicating retardance and slow-axis orientation of the third mosaic birefringent mask according to an exemplary embodiment. In an exemplary embodiment, the mosaic birefringent mask of FIG. 3A may be added to a polarization image sensor (e.g., Sony's polarization image sensor) for use in quantitative instant polarization microscopy. This design does not include the use of a circular polarizer. As shown in FIG. 3B, the superpixel of the mask includes four pixels with a retardation of 0.25λ. The slow-axis orientation φ of the superpixel is φ=5° at the first pixel position 300, φ=50° at the second pixel position 305, φ=95° at the third pixel position 310, and φ=140° at the fourth pixel position 315.

[0021] FIG. 4A shows a pattern of the fourth mosaic birefringent mask according to an exemplary embodiment. FIG. 4B shows an example of a basic group of four mosaic squares with colors indicating retardance and slow-axis orientation of the fourth mosaic birefringent mask according to an exemplary embodiment. In the embodiment of FIG. 4, the white squares of the mask are not birefringent. The superpixel of the mask includes four pixels, three of which are shaded pixels with retardation of 20 nm (~0.03 λ), and the white pixel (at the first pixel position 400) has no retardation. The slow-axis orientation of the superpixel is 0° at the second pixel position 405, 45° at the third pixel position 410, and 90° at the fourth pixel position 415. The proposed third mosaic birefringent mask is designed to work with an asymmetric four-frame algorithm with extinction setting. It should be noted that this algorithm is less sensitive and its sensitivity depends on the sample orientation. In alternative embodiments, additional tessellated birefringent mask configurations that work with the four-frame algorithm can be used. Additional mask configurations for the two-frame, three-frame, and five-frame algorithms can also be created, but such configurations are not believed to be optimal, nor have they been found to provide any additional benefit.

[0022] Similar to the Bayer color filter array (e.g., red, blue, and two green filters), the proposed birefringent mask can be implemented in many different ways. For example, FIG. 5A shows an example of a first mosaic birefringent mask configuration implemented with two basic groups according to an exemplary embodiment. The smaller group covers a 2×2 pixel area, and the larger group covers a 4×4 pixel area. Thus, the mask can work in two modes: (1) a high-resolution mode when more light is available, and (2) a low-sensitivity mode when illumination is weak. FIG. 5B shows four variations of a basic group with four (2×2) mosaic squares according to an exemplary embodiment. FIG. 5C shows a basic group with 16 (4×4) mosaic squares according to an exemplary embodiment. 5, the white square 500 is not birefringent, and the first shaded (e.g., red) square 505, the second shaded (e.g., green) square 510, and the third shaded (e.g., blue) square 515 have retardance of 20 nm (~0.03λ) and slow-axis orientations of 0°, 60°, and 120°, respectively. As shown, adjacent mosaic squares can be combined to form one larger unit.

[0023] The principle scheme of an instant polarizing microscope with a mosaic birefringent mask is described below. In an exemplary embodiment, the proposed mosaic birefringent mask is placed in a polarizing microscope between crossed circular or near-circular polarizers. The mosaic squares are either placed directly on the image sensor or in a conjugate plane with the sensor. FIG. 6 shows an example of an instant polarizing microscope with a mosaic birefringent mask and a circular polarizer attached directly to the image sensor (photodiode array) according to an exemplary embodiment. FIG. 6 also shows the light transmission path in the microscope. In FIG. 6, Sc is the light source (e.g. laser, light emitting diode), F is a bandpass filter, LCP is a left-handed circular polarizer, RCP is a right-handed circular polarizer, C is a condenser, Sp refers to the sample under analysis, and O is the objective lens. In alternative embodiments, the microscope of FIG. 6 may have fewer, additional, and / or different components.

[0024] 7 shows an example of an instantaneous polarizing microscope in which a mosaic birefringent mask and a circular polarizer are disposed in a conjugate plane (i.e., an intermediate image plane) with an image sensor, according to an exemplary embodiment. In this embodiment, an objective lens creates an image of the sample on the mosaic mask, and a projection lens images the mosaic mask and the sample onto the image sensor. In addition to the various components shown in FIG. 6, the embodiment of FIG. 7 includes a projection lens (or relay lens), indicated by L in the figure.

[0025] Figure 8 is a schematic diagram of an instantaneous polarizing microscope with a reflected light path, according to an exemplary embodiment. In the embodiment of Figure 8, a circularly polarized beam is reflected by a non-polarizing beam splitter toward the sample. In this example, the mosaic birefringent mask is placed directly on the image sensor. In addition to the various components shown in Figures 6 and 7, the embodiment of Figure 8 also includes a non-polarizing beam splitter, which is indicated in the figure by NPBS.

[0026] FIG. 9 shows a mosaic birefringent mask written (nanomachined) inside a quartz substrate by laser pulses according to an exemplary embodiment. The image in FIG. 9 was taken by a polychromatic polarizing microscope. In FIG. 9, the hue corresponds to the slow-axis orientation and the brightness is proportional to the retardation. The mask is designed to work with a Lumenera camera Infinity 8-2M. The mask's superpixel contains four pixels, where the first pixel 900, the second pixel 905, and the third pixel 910 have a retardation of 20 nm, and the fourth pixel 915 has no retardation. Additionally, the first pixel 900 has a slow-axis orientation of φ=0°, the second pixel 905 has a slow-axis orientation of φ=60°, and the third pixel 910 has a slow-axis orientation of φ=120°. The pixel size of the tessellated mask is 9 μm×9 μm, which is equal to the pixel size in the Infinity 8-2M. In alternative embodiments, the tessellated mask may have different pixel sizes to suit different types of cameras (i.e., image sensors).

[0027] 10 shows an instantaneous polarizing microscope with a mosaic birefringent mask and a polarizing image sensor according to an exemplary embodiment. In an exemplary embodiment, the polarizing image sensor can be a Sony polarizing image sensor with an on-chip lens, a polarizer, and a photodiode. In an alternative implementation, the embodiment of FIG. 10 can also include a relay lens (or projection lens) similar to the embodiment of FIG. 7.

[0028] In an exemplary embodiment, all possible states of polarization can be represented by a set of four real numbers called the Stokes parameters. The Stokes parameters each have the dimension of intensity. In terms of Cartesian coordinates, the four Stokes parameters, denoted by S0, S1, S2, and S3, are defined as follows:

[0029]

number

[0030] In particular, I0 denotes the total intensity of the light wave, and I x , I y , I +45゜ , I -45゜ , I r , and I l denotes the intensity transmitted by an ideal variable polarizer placed in the wave path and adjusted to transmit linearly polarized light oriented at x, y, +45°, -45°, and (l) left-handed and (r) right-handed circularly polarized light, respectively. These polarizations are called degenerate polarizations. The proposed mosaic birefringent mask can be used for instantaneous mapping of all Stokes parameters. Such a device is called an instant imaging full Stokes polarimeter. In the following, three examples for instant imaging full Stokes polarimeters are outlined.

[0031] FIG. 11 shows a first mosaic birefringent mask for imaging full Stokes polarization parameters using a polarization imaging chip according to an exemplary embodiment. The top row of FIG. 11 shows the combination of the proposed mosaic birefringent mask and the mosaic polarizing mask covering the image sensor. The combination of the polarizing mask and the image sensor is called a polarized image sensor, which is currently available on the market (e.g., Sony IMX250MZR). The bottom row shows the superpixels in the birefringent mask and the polarizing mask and their mutual arrangement. The birefringent superpixel is formed from three pixels with no birefringence and a birefringent pixel with a quarter-wave retardation (Δ=λ / 4) and a horizontal slow axis (φ=0°). The polarizing superpixel is formed from four micropolarizers with principal axes oriented in the horizontal (x), vertical (y) and ±45° directions. The superpixels of the image sensor generate signals I1, I2, I3, and I4 that allow the calculation of all the Stokes parameters as follows:

[0032]

number

[0033] Currently available polarization image sensors use wire grid micropolarizers and work relatively well in the longer wavelength range, spanning from green to near infrared light. To work in the shorter wavelength range, including blue, violet, and near ultraviolet light, a polarimeter configuration can be used as shown in FIG. 12. The top row of FIG. 12 shows the proposed combination of a mosaic birefringent mask, a circular polarizer, and an image sensor. The bottom row displays a superpixel in the birefringent mask, a region of the circular polarizer, and the corresponding image sensor superpixel. The birefringent superpixel is formed from one pixel with no birefringence and three birefringent pixels with quarter-wave retardation (Δ=λ / 4) and horizontally and diagonally oriented slow axes (φ=−45°, 0°, +45°). The image sensor superpixel generates signals I1, I2, I3, and I4, which allow the calculation of all Stokes parameters using equation (2) above.

[0034] The two schematic polarimeters above perform summation to calculate the three Stokes parameters. Therefore, these implementations may result in increased noise and reduced sensitivity. The polarimeter schematic in FIG. 13 performs only difference operations. FIG. 13A shows a mosaic birefringent mask for imaging full Stokes parameters using a polarization imaging chip according to an exemplary embodiment. FIG. 13B shows two superpixels of the mosaic birefringent mask according to an exemplary embodiment. FIG. 13C shows two sets of six signals generated by two superpixels of the mosaic birefringent mask according to an exemplary embodiment. In the embodiment of FIG. 13, the proposed mosaic mask is used in combination with a polarization image sensor (e.g., the Sony polarization imaging chip mentioned above), which allows the device to receive all four Stokes polarization parameters of an image. The mask contains two sets of superpixels with six pixels each, in which the four right-hand pixels are not birefringent and the two left-hand birefringent pixels have quarter-wave retardation (Δ=λ / 4). The hatch pattern orientation indicates the slow-axis orientation, which is −45° and 0° in the first superpixel and 90° and 45° in the second superpixel.

[0035] The superpixels of the first image sensor produce a signal I that allows all the Stokes parameters to be calculated as 11 , I 12 , I 13 , I 14 , I 15 , and I 16 Generate.

[0036]

number

[0037] The superpixels of the second image sensor produce a signal I that allows all the Stokes parameters to be calculated as21 , I 22 , I 23 , I 24 , I 25 , and I 26 Generate.

[0038]

number

[0039] Thus, described herein is a method and system for a nano-engineered mosaic birefringent mask with attached uniform circular polarizer that can be added to a photodiode array. The proposed sensor has instantaneous and high sensitivity to small changes in polarization in the image. In one implementation, the mosaic birefringent mask described above can be incorporated into an instant polarizing microscope to create a more sensitive polarization image sensor with reduced polarization distortion. In another implementation, the mosaic birefringent mask can be used to create an instant full Stokes camera with instant full Stokes polarization parameter imaging.

[0040] In an exemplary embodiment, the operation of the instant polarizing microscope or full Stokes camera may be performed by a computing system including a processor, memory, a user interface, a transceiver (i.e., a receiver and / or a transmitter), etc. Instructions for operating the microscope / camera may be stored in the memory, and when executed by the processor, the computing system may control the operation of the device. All or a portion of the computing system may be incorporated into the microscope in an embodiment. All or a portion of the computing system may be in the form of a system remote from the microscope and used to control and / or operate the system. As an example, FIG. 14 is a block diagram of a computing system 1400 for implementing a microscope imaging system according to an exemplary embodiment. The computing system 1400 may communicate with other computing devices (e.g., servers, processors) directly or through a network 1435, depending on the implementation.

[0041] The computing system 1400 includes a processor 1405, an operating system 1410, a memory 1415, an input / output (I / O) system 1420, a network interface 1425, and an imaging application 1430. In alternative embodiments, the computing system 1400 may include fewer components, additional components, and / or different components. The components of the computing system 1400 communicate with each other via one or more buses or any other interconnect system. In embodiments where the computing system is remote from the microscope, the computing system 1400 may be any type of computing device (e.g., tablet, laptop, desktop, smartphone) having sufficient processing power to perform the operations described herein.

[0042] The processor 1405 may be in electronic communication with and used to control any of the components of any of the systems described herein. For example, the processor may be used to execute the imaging application 1430, process received user selections, send data and commands to the microscope and / or imaging sensor, receive raw data from the microscope and / or imaging sensor and process the data using algorithms described herein, etc. The processor 1405 may be any type of computer processor in the art and may include multiple processors and / or multiple processing cores. The processor 1405 may comprise a controller, a microcontroller, an audio processor, a graphics processing unit, a hardware accelerator, a digital signal processor, etc. Furthermore, the processor 1405 may be implemented, for example, as a complex instruction set computer (CISC) processor, as a reduced instruction set computer (RISC) processor, as an x86 instruction set computer processor. The processor 1405 is used to run an operating system 1410, which may be any type of operating system.

[0043] The operating system 1410 is stored in memory 1415, which is also used to store programs, microscope data, readings and settings, network and communication data, peripheral data, imaging applications 1430, and other operating instructions. The memory 1415 can be one or more memory systems including various types of computer memory, such as flash memory, random access memory (RAM), dynamic RAM (DRAM), static RAM (SRAM), universal serial bus (USB) drives, optical disk drives, tape drives, internal storage devices, non-volatile storage devices, hard disk drives (HDD), volatile storage devices, and the like. In some embodiments, at least a portion of the memory 1415 may reside in the cloud to provide cloud storage for the system. Similarly, in one embodiment, any computing element described herein (e.g., processor 1405) may be implemented in the cloud such that the system can be run and controlled via cloud computing.

[0044] The I / O system 1420 is a framework that allows users and peripheral devices to interact with the computing system 1400. The I / O system 1420 may include a display, one or more speakers, one or more microphones, a keyboard, a mouse, one or more buttons or other controls, etc. that allow a user to interact with and control the computing system 1400. The I / O system 1420 also includes circuitry and bus structures that interface with peripheral computing devices, such as power sources, USB devices, data acquisition cards, peripheral component interconnect express (PCIe) devices, serial advanced technology attachment (SATA) devices, high-definition multimedia interface (HDMI) devices, proprietary connection devices, etc.

[0045] The network interface 1425 includes transceiver circuitry (e.g., transmitters and receivers) that enable the computing device 1400 to send and receive data to / from other devices, such as remote data processing centers, individual microscope units, servers, websites, etc. The network interface 1425 enables communication over a network 1435, which may be one or more communications networks. The network 1435 may include cable networks, fiber networks, cellular networks, Wi-Fi networks, landline telephone networks, microwave networks, satellite networks, etc. The network interface 1425 also includes circuitry that enables device-to-device communication, such as Bluetooth®.

[0046] The imaging application 1430 may include software and algorithms in the form of computer readable instructions that, when executed by the processor 1405, perform any of the various operations described herein, such as controlling a light source, controlling an imaging sensor, extracting data from captured images, calculating Stokes parameters, etc. The imaging application 1430 may utilize the processor 1405 and / or memory 1415 discussed above. In alternative embodiments, the imaging application 1430 may be remote or independent from the computing device 1400, but in communication with it.

[0047] The word "exemplary" is used herein to mean serving as an example. Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Further, for purposes of this disclosure, unless otherwise specified, the words "a" and "an" mean "one or more."

[0048] The foregoing description of exemplary embodiments of the present invention has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or can be acquired from the practice of the present invention. The embodiments have been chosen and described in order to explain the principles of the invention and as practical applications of the invention to enable those skilled in the art to utilize the invention in various embodiments and with various modifications suitable for the particular applications contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. The present disclosure also includes the following aspects. [Aspect 1] 1. A polarizing microscope, comprising: a light source configured to illuminate the sample; an image sensor configured to capture an image of the sample; a first circular polarizer disposed between the light source and the sample; a mosaic birefringent mask disposed between the sample and the image sensor; a second polarizer disposed between the mask and the image sensor; A polarizing microscope equipped with a [Aspect 2] 2. The microscope of claim 1, wherein the second polarizer and the mosaic birefringent mask are attached to the image sensor. [Aspect 3] 2. The microscope of claim 1, wherein the second polarizer and the mosaic birefringent mask are disposed in a plane conjugate with the image sensor. Aspect 4 2. The microscope of claim 1, further comprising an objective lens disposed between the sample and the mosaic birefringent mask. Aspect 5 2. The microscope of embodiment 1, wherein the second polarizer comprises a circular polarizer. Aspect 6 2. The microscope of embodiment 1, wherein the second polarizer comprises a right-handed circular polarizer and the first polarizer comprises a left-handed circular polarizer. Aspect 7 2. The microscope of claim 1, wherein the superpixel of the mosaic birefringent mask comprises a first square, a second square, a third square, and a fourth square having a retardation range of 0 to 0.25λ. Aspect 8 8. The microscope of claim 7, wherein the first square is not birefringent, the second square, the third square, and the fourth square have equal retardation in the range of 0.01λ to 0.25λ, and the second square has a slow axis orientation that is 0°, the third square has a slow axis orientation that is 60°, and the fourth square has a slow axis orientation that is 120°. Aspect 9 8. The microscope of claim 7, wherein the first square is not birefringent, the second square, the third square, and the fourth square have equal retardation in the range of 0.01λ to 0.25λ, and the second square has a slow axis orientation that is 0°, the third square has a slow axis orientation that is 45°, and the fourth square has a slow axis orientation that is 90°. Aspect 10 8. The microscope of claim 7, wherein the first square, the second square, the third square, and the fourth square have equal retardation in the range of 0.01λ to 0.25λ, and the first square has a slow axis orientation that is 0°, the second square has a slow axis orientation that is 45°, the third square has a slow axis orientation that is 90°, and the fourth square has a slow axis orientation that is 135°. Aspect 11 2. The microscope of claim 1, wherein the mosaic birefringent mask comprises two sets of superpixels. Aspect 12 2. The microscope of embodiment 1, wherein the mosaic birefringent mask is produced by laser pulses directed into a quartz substrate. Aspect 13 2. The microscope of claim 1, wherein the mosaic birefringent mask is formed by a nanostructured surface. Aspect 14 2. The microscope of embodiment 1, wherein the mosaic birefringent mask is composed of microtiles made from a birefringent film. Aspect 15 1. An instant imaging full Stokes polarimeter, comprising: a polarization image sensor including a polarizer and an image sensor; a mosaic birefringent mask proximate to the polarization image sensor, the mosaic birefringent mask comprising a plurality of birefringent superpixels, each birefringent superpixel being formed from one or more non-birefringent pixels and one or more birefringent pixels; a processor operatively coupled to the polarization image sensor, the processor configured to process a plurality of intensity signals generated by a plurality of the birefringent superpixels to determine Stokes parameters of an image captured by the image sensor; An instant imaging full Stokes polarimeter comprising: Aspect 16 16. The polarimeter of embodiment 15, wherein the polarizer comprises a mosaic polarizing mask comprising a plurality of polarization superpixels, and each polarization superpixel comprises a plurality of micropolarizers. Aspect 17 16. The polarimeter of embodiment 15, wherein the polarizer comprises a circular polarizer. Aspect 18 16. The polarimeter of claim 15, wherein the mosaic birefringent mask is attached to one or more of the image sensor and the polarizer. Aspect 19 16. The polarimeter of embodiment 15, wherein the mosaic birefringent mask comprises two sets of superpixels. Aspect 20 16. The polarimeter of embodiment 15, wherein each birefringent superpixel includes six pixels.

Claims

1. 1. A polarizing microscope, comprising: a light source configured to illuminate the sample; an image sensor configured to capture an image of the sample; a first circular polarizer disposed between the light source and the sample; a mosaic birefringent mask disposed between the sample and the image sensor; a second polarizer disposed between the mask and the image sensor; A polarizing microscope equipped with a

2. 2. The microscope of claim 1, wherein the second polarizer and the mosaic birefringent mask are attached to the image sensor.

3. The microscope of claim 1 , wherein the second polarizer and the mosaic birefringent mask are disposed in a plane conjugate with the image sensor.

4. The microscope of claim 1 , further comprising an objective lens disposed between the sample and the mosaic birefringent mask.

5. The microscope of claim 1 , wherein the second polarizer comprises a circular polarizer.

6. 2. The microscope of claim 1, wherein the second polarizer comprises a right-handed circular polarizer and the first polarizer comprises a left-handed circular polarizer.

7. 2. The microscope of claim 1, wherein the superpixels of the mosaic birefringent mask comprise a first square, a second square, a third square, and a fourth square having a retardation range of 0 to 0.25λ.

8. 8. The microscope of claim 7, wherein the first square is not birefringent, the second square, the third square, and the fourth square have equal retardation in the range of 0.01λ to 0.25λ, and the second square has a slow axis orientation that is 0°, the third square has a slow axis orientation that is 60°, and the fourth square has a slow axis orientation that is 120°.

9. 8. The microscope of claim 7, wherein the first square is not birefringent, the second square, the third square, and the fourth square have equal retardation in the range of 0.01λ to 0.25λ, and the second square has a slow axis orientation that is 0°, the third square has a slow axis orientation that is 45°, and the fourth square has a slow axis orientation that is 90°.

10. 8. The microscope of claim 7, wherein the first square, the second square, the third square, and the fourth square have equal retardation in the range of 0.01λ to 0.25λ, and the first square has a slow axis orientation that is 0°, the second square has a slow axis orientation that is 45°, the third square has a slow axis orientation that is 90°, and the fourth square has a slow axis orientation that is 135°.

11. The microscope of claim 1 , wherein the mosaic birefringent mask comprises two sets of superpixels.

12. 10. The microscope of claim 1, wherein the mosaic birefringent mask is created by laser pulses directed into a quartz substrate.

13. The microscope of claim 1 , wherein the mosaic birefringent mask is formed by a nanostructured surface.

14. 2. The microscope of claim 1, wherein the mosaic birefringent mask is constructed from microtiles made from a birefringent film.

15. 1. An instant imaging full Stokes polarimeter, comprising: a polarization image sensor including a polarizer and an image sensor; a mosaic birefringent mask proximate to the polarization image sensor, the mosaic birefringent mask comprising a plurality of birefringent superpixels, each birefringent superpixel being formed from one or more non-birefringent pixels and one or more birefringent pixels; a processor operatively coupled to the polarization image sensor, the processor configured to process a plurality of intensity signals generated by a plurality of the birefringent superpixels to determine Stokes parameters of an image captured by the image sensor; An instant imaging full Stokes polarimeter comprising:

16. 16. The polarimeter of claim 15, wherein the polarizer comprises a mosaic polarizing mask comprising a plurality of polarization superpixels, and each polarization superpixel comprises a plurality of micropolarizers.

17. The polarimeter of claim 15 , wherein the polarizer comprises a circular polarizer.

18. The polarimeter of claim 15 , wherein the mosaic birefringent mask is attached to one or more of the image sensor and the polarizer.

19. The polarimeter of claim 15 , wherein the mosaic birefringent mask comprises two sets of superpixels.

20. The polarimeter of claim 15 , wherein each birefringent superpixel includes six pixels.

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