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In this study, an interferometric method was proposed for the simultaneous measurement of phase retardation and fast-axis azimuth angle of a wave plate by using a Mach–Zehnder interferometer. The w...

Beam shaping is required for semiconductor lasers to achieve high optical fiber coupling efficiency in many applications. But the positioning errors on optics may reduce beam shaping effects, and then lead to low optical fiber coupling efficiency. In this work, the positioning errors models for the single emitter laser diode beam shaping system are established. Moreover, the relationships between the errors and the beam shaping effect of each shapers are analysed. Subsequently, the relationship between the errors and the optical fiber coupling efficiency is analysed. The result shows that position errors in the Z axis direction on the fast axis collimator have the greatest influence on the shaping effect, followed by the position errors in the Z axis direction on the converging lens, which should be strictly suppressed in actual operation. Besides, the position errors have a significant influence on the optical fiber coupling efficiency and need to be avoided.

We present a beam combination technique to improve the brightness of diode lasers based on both spectral beam combination and polarization beam combination. We use eight diode laser arrays (DLAs) and two diffraction gratings to construct two independent external cavities by using spectral beam combination, and then combine the outputs of these two cavities by using polarization beam combination. The experiment shows that the total output power can be as high as 310.2 W by using this technique with eight DLAs, which are commercial standard cm-bars, each producing ∼60 W of output power. The beam qualities of the combined beam are M2 = 13.55 and 10.27 in the slow and fast axis, respectively. The brightness of the combined output is as high as 252 MW·cm−2·sr−1.

We present a serpentine-based 16-element dispersive OPA at very near-IR wavelengths that leverages SiN waveguide feeding. 2D beam steering is achieved by wavelength sweep, with tunability of 0.11°/nm on slow and 3.52°/nm on fast axis.

In this paper, the research work of two-dimensional beam shaping and homogenization of high power laser diode (LD) stack by a rectangular waveguide is presented. Both the theoretical simulation and experiment results have shown that the diode stack beam can be shaped into a uniform square spot with a dimension of 10 mm × 10 mm and the non-uniformity less than 5% along both directions of slow axis and fast axis, the shaped beam has a uniform pumping depth over 10 mm, which is well to be used for a rectangular laser medium end pumping.

We propose a two-axis electromagnetic micro scanner with a two-phase current path satisfying three criteria (via less microfabrication, independent biaxial scan with minimization of crosstalk, and no current path on the mirror). In the design of a dual radial magnetic field, current paths are arranged to maximize the torque in the active current that actuates a mirror, while nullifying the torque in the passive current that is not intended to actuate the mirror but rather just to complete an electrical current loop. The use of W-shaped springs for the slow-axis scan considerably reduced the torsional spring constant by 2.7 times, whereas it increased the in-plane sliding spring constant by 2.4 times, compared to conventional I-shaped springs. This indicates that the W-shaped springs effectively increase scan angle and enhance the actuation stability. The scanner with a reflection mirror with 3 mm in diameter was fabricated, and in the raster scan gave a maximum scan angle of 50.6° (resonant) and 9.1° (quasi-static) in fast- and slow-axis scans, respectively, with a power consumption of 28.1 mW. The maximum crosstalk of the slow and fast axis from the other axis were measured as small as 0.45% and 0.43%, respectively.

This work aims to characterize the retardation of birefringent samples such as wave-plates and birefringent wedges where the principal axis is uniform over the sample zone. The in-line procedure described and implemented for the purpose uses four frames of intensity data that are digitally recorded and combined to characterize the sample in terms of its retardance from 0 to 2π as also to uniquely identify the direction of its fast axis. Simulated and experimental results presented are in good agreement with the proposed theory.

A blind-angle calibration method is introduced for self-spectral calibration of a compound zero-order waveplate. By rotating the waveplate at blind detection angles, the wavelength-dependent retardance and the orientation of the effective fast axis can be determined through iterative least-squares calculations of the spectra measured by a multi-channel spectrometer. Excellent agreement between the experimental values and the theoretical values is achieved, indicating that the new method can be used as a reliable way to calibrate compound zero-order wave plates. Using the new method, there is no need to rotate the waveplate at specific detection angles. A high-precision waveplate holder or complex adjustment procedure is not required.

We report the measurement of bending-induced birefringence in the presence of large intrinsic birefringence in a hollow-core photonic crystal fiber (HC-PCF). The fast axis of bending-induced birefringence was found to be normal to the bending plane, in contrast to the conventional fiber case. The dependence of the induced birefringence on the bending radius was also different from the typical inverse square law. Possibilities and design criteria for polarization controllers using bending-induced birefringence in HC-PCFs are presented.

In order to solve the problem of low efficiency and low accuracy of manually picked fast shaft collimation lens in actual production, the method of recognition of fast shaft collimation lens based on machine vision is studied. Using industrial camera to achieve image acquisition, using HALCON software to pre-process the image of fast-axis collimated lens, edge detection and other aspects of research, through the platform verification, the results show that the processed image is clear and easy to identify. In the lens placement is not accurate, the background is dirty can still ensure a better positioning effect, This study has some reference significance for visual recognition in the actual production of fast-axis collimation lens.

Optical components with complex surfaces are widely applied. Ultra-precision diamond turning technology can fabricate these complex surfaces efficiently and accurately. Fast axis servo (FAS) system has the characteristics of large stroke and high frequency response. In this paper, Fast axis servo system based on linear rolling guide rail was used to process the complex surface. By the speed/acceleration feedforward and the position PID feedback control algorithm, the precision motion control of the fast axis servo system in large stroke and high frequency was realized. According to the principle of fast axis servo machining, the tool path generating for FAS cutting and machining surface simulation were carried out. The Machining experiments of typical complex surfaces were tested and analyzed, the results show that this method can produce the expected complex surface shape and has preferable servo machining performance.

In this study, an optical scheme based on the measurement of light intensity and a proper orientation of the Fresnel Rhomb is successfully developed for simultaneous determination of the phase retardation and fast axis of a wave plate. The theoretical analysis of the principle of measuring the reflection-induced retardance of the Fresnel Rhomb and the phase retardation of a wave plate is given taking Stokes–Mueller Formalism as a mathematical tool. In this method, the fast axis position of the wave plate need not be determined in advance. In addition, the measured result is free of the intensity fluctuation of light source. An application example is also demonstrated. The measured result of the example is verified with an experiment. Some of the merits of the method, such as, a simple optical set-up, high stability and high accuracy, low cost and easier operation, are presented, and the validity of the method is demonstrated.

It is vitally important to numerically simulate the output power spatial distribution of diode laser stacks when they are used in beam shaping and pumping for other lasers. Here, we propose a numerical simulation technique by considering the discreteness of the propagation angles of individual emitters in diode laser stacks in the fast axis. Using this proposed simulation technique, we calculated the spatial distribution of the outputs of the four diode laser stacks and the total output power of the 3000 W fiber-coupled diode laser. The calculated results agree well with the experimentally measured values. Therefore, when designing a laser, this is a useful way to select diode laser stacks based on specifications.

The smile effect is inevitable during the packaging process of diode laser stacks. Position errors and direction errors are used to describe the smile effect. A theoretical smile model has been built, and a beam propagation model of the external cavity has been further proposed based on the smile model. Beam properties such as spectrum, intensity distribution, and beam quality of combined beams have been simulated and discussed. The results show that position errors have little impact on intensity distribution of combined beams but make spectrum slightly broadened. Direction errors make intensity generate side lobes and degrade beam quality significantly. Compared with position errors, direction errors in both slow axis and fast axis have more detrimental effect on output beams. Thus, it is more important to control angle deflection of beams than positions of emitters during the manufacturing process of DLSs.

High-precision chalcogenide molded freeform micro-lenses were designed and produced to perfectly collimate and circularize mid-infrared Quantum Cascade Lasers (QCLs). The innovative micro-lens has an input surface with freeform contour to simultaneously converge the fast axis and further diverge the slow axis, while the output freeform surface collimates both axes. The 5-mm long freeform lens is such that the collimated output fast- and slow-axis beams are circular. This paper presents recent results on the chalcogenide molded freeform micro-lens prototypes specifically designed to collimate and circularize QCL at 9 micron.

The design and characterization of a two-degree-of-freedom serial kinematic microelectromechanical systems (MEMS) nanopositioner for on-chip atomic force microscopy (AFM) is reported. A novel design is introduced to achieve a serial kinematic mechanism based on a standard silicon-on-insulator MEMS fabrication process. The nanopositioner comprises a slow axis with a resonance frequency of 2.4 kHz and a fast axis with a resonance frequency of above 4.4 kHz, making it ideal for rastering, as required in the AFM. Strokes of 14 and $9\,\, \mu \text{m}$ are experimentally achieved for the fast and slow axes, respectively. The serial kinematic design of the stage enables the cross-coupling between the two axes of motion to be as low as −60 dB. Electrothermal displacement sensors are incorporated in the device, which may be used to enable feedback control as required in high-speed AFM. [2014-0248]

We present a technique and algorithm for measuring the phase retardation of a wave plate based on spectral transmission curve. Through accurately extracting the intersection points' wavelengths from the spectral transmission curve, the effective phase retardation, absolute phase retardation, order, and physical thickness of the wave plate can be measured simultaneously in a wide spectral range. Experimental results show that the proposed technique has many advantages, such as higher data utilization, simpler extraction algorithm, and no strict requirement for the directions of transmission axes of the polarizer and analyzer, and the fast axis of the wave plate.

Low SMILE vertically stacked laser bars gold/tin (AuSn) soldered on nearly symmetrical micro channel coolers were designed, built and characterized. 96% of 200 measured SMILE (bowing) values are less than 2 μm. Twenty-one 5×1 vertical stacks have a divergence of 2.03mrad with a standard deviation of 0.19mrad after fast axis collimation. A line laser module was built with twelve 5×1 vertical stacks to produce 6 KW in a line geometry of 0.6 mm@1/e2 by 285 mm @85% and a line uniformity of 86%. Several laser line modules can horizontally be connected to form a wider line for glass surface treatment and thin film solar panel processing.

In this paper, analysis of beam shaping and homogenization of high power diode laser stack into a line focus with dimension of 10 mm × 0.5 mm was reported. The beam shaping and homogenization was simulated by using ZemaX-ray tracing technique. The results have shown that intensity distribution after beam shaping and homogenization at the work piece is a flat top for the slow axis with homogeneity over 95% and a Gaussian distribution for the fast axis.

This study presents an innovative dual-screen projection system (DSPS) based on a balance-type dual micromirror structure. This design solves the problem of existing micro-projectors only being able to display a single small picture. The proposed balance-type dual micromirror structure was fabricated using a signal-mask LIGA-like technology with piezoelectric actuation to form a DSPS. The DSPS consists of dual micromirrors as a fast axis, an eccentric structure as a slow axis, and slender piezoelectric actuators. A Y-shaped beam connects two micromirrors to achieve a balance-type dual micromirror structure in which the synchronous scanning of both micromirrors form motion behaviors that approximate to a balance. Experimental results show that the driving frequencies of the slow axis and the fast axis are 3.75 kHz and 11.7 kHz, respectively. The mechanical deflection angles of the slow axis and the fast axis are capable of achieving 2° and 9.6°, respectively, with an applied voltage of 30 V pp . The device can simultaneously display DSPS scanning pictures in a Lissajous scanning manner as dual square patterns, dual heart patterns, a pair of rectangular patterns, and a pair of elliptical patterns. The proposed device achieves the simultaneous display of two patterns with a projection resolution of 320 × 240. Therefore, this DSPS is applicable in scenarios that require dual identical projection screens, such as head-up and head-mounted displays, and when two identical images are needed for both the left and right eyes.

We show that there are a number of ways to transform an arbitrary polarization state into another with just two quarter wave plates (QWPs). We have verified this geometrically using the trajectories of the initial and final polarization states corresponding to all the fast axis orientations of a QWP on the Poincare sphere. The exact analytical expression for the locus of polarization states has also been given, and describes the trajectory. An analytical treatment of the equations obtained through matrix operations corresponding to the transformation supports the geometrical representation. This knowledge can be used to obtain the Mueller matrix by just using QWPs, which has been shown experimentally by exploiting projections of the output states on the input states.

Mode-locked fiber lasers are the most promising lasers for intracavity phase interferometry, 1 because they offer the possibility to have two orthogonally polarized pulses circulating independently in the cavity. The saturable absorbers based on polarization maintaining tapered fiber coated with carbon nanotubes are developed and analyzed for minimum coupling between the slow and fast axis of the fiber.

The performance of a Ti:sapphire laser pumped by a single 461 nm laser diode is presented for both the continuous-wave and the mode-locked regimes of operation. We introduce a simple astigmatism correction scheme for the laser diode beam consisting of two cylindrical lenses affecting the pump beam along the fast axis of the laser diode, which provides the mode-matching between the nearly square-shaped pump beam and the cavity mode. The resulting efficiency of the suggested Ti:Sapphire oscillator pumped by such a laser diode is analyzed for the Ti:sapphire crystals of 3 mm, 5 mm and 10 mm in length. We demonstrate that such a system provides the generation of ultrashort pulses up to 15 fs in duration with the repetition rate of 87 MHz, the average power being 170 mW.

Intra-cavity phase anisotropy causes each laser longitudinal mode to split into two orthogonally polarized frequencies. When the frequency difference generated by small anisotropy is about 40 MHz or less, only one frequency of the splitting mode oscillates while the other is always in lock-in state due to strong mode competition. In that case the longitudinal mode spacing deviates from its original value. And the spacing of two adjacent longitudinal modes shows differential variations depending on direction of cavity length tuning and mode polarization. In this paper, the relationship between spacing variation and small intra-cavity anisotropy is demonstrated experimentally and theoretically. The equivalent fast axis of anisotropy is determined additionally by its correlation with laser intensity tuning of the two orthogonally polarized components. The novel measurement method is successfully tested in several applications.

Regeneration of fibre Bragg gratings under application of a high temperature annealing process in a high birefringent polarisation maintaining fibre of type Panda was investigated. During the annealing process, a distinct nonlinearity and hysteresis of the birefringence with temperature was observed. After the temperature process, the birefringence between slow and fast axis at room temperature was nearly doubled, which is in agreement with observations of other researchers. The hysteresis in birefringence might be explained by the crossing of the transition temperature of the stress applying parts and the relief of in-frozen mechanical and thermal stresses.

We present a method for calibration and data extraction for a nonoptimized Mueller matrix polarimeter. The advantage of this type of method is a reduction in measurement time for multiwavelength systems or in systems with slow response times. The calibration process requires the measurement of four known polarization devices. Here we use free-space transmission, a horizontal and a vertical linear polarizer, and a quarter-wave retarder with its fast axis at 30° to the horizontal. Experimental measurements of rotating quarter-wave and half-wave retarders show that accurate results can be obtained with the proposed method.

Transforming polarization states of light from one to another in a controlled manner can be achieved with a minimal gadget consisting of two-quarter waveplates. Using a geometric approach, we demonstrate this result for transforming any completely polarized states of light (CPSL) to any other CPSL, including the orthogonal states. Furthermore, we describe a working algorithm for identifying the fast axis setting of the two-quarter waveplates essential for the state transformation.

An automated Stokes-polarimeter with a rotating phase plate has been developed to measure the polarization characteristics of radiation reflected and scattered by objects at different angles to the surface. An estimate is made of the systematic error due to variation of the initial position of the fast axis of the phase plate and deviation of the phase difference of the λ/4 plate from 90°.

A phase step interferometry system using polarization shifting is described. The device is essentially a Mach-Zehnder interferometer in which the polarization of light travelling through one arm is orthogonal to the polarization of light travelling through the other arm. At the interferometer output we place a quarter-wave plate with its fast axis at with respect to the polarization directions and a polarizer. By rotating the polarizer, the interfering waves acquire an extra phase (of topological origin) to that expected from the calculations of optical path lengths, and thus, arbitrary phase shifts can be induced. Then, from a set of interferograms recorded while the reference phase is changed, the `dynamical' phase difference (e.g. the phase profile of an object placed in one of the interferometer arms) can be reconstructed by using techniques of phase-shifting interferometry.

We present a birefringence analysis method based on polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) for distinguishing pearls. To cope with the round shape of general pearls, a rotation stage was used for the sample scanning. With the system, the birefringence of several cultured pearls including south sea, Akoya, freshwater cultured pearls, and imitation pearls are analyzed and compared. Interestingly, PS-SS-OCT surely shows well developed birefringence patterns of phase retardation and fast axis orientation with the cultured pearls, whereas the pattern does not appear in the imitation pearls. In addition, the intensity image can help to distinguish the cultured pearls. Therefore, PSSS-OCT enables a more accurate interpretation for identifying the cultured pearls from imitation pearls.

Direct drives and ball screw drives are the most promising feed drive systems for high speed machining. For optimum performance the drives and the feedback control system must be exploited to their physical limits. Thus, input saturation of the feed drives becomes a very important design parameter. A new design method based on a nonlinear stability analysis has been developed to take this into account. The improvements regarding machine tool design and the selection of suitable drive systems made possible by this method are shown and discussed.

Misalignment errors of the composite wave-plate, a typical kind of compensator used in spectroscopic ellipsometers (SE), can lead to spurious oscillations in the SE measurement. In this paper, we construct an equivalent model of the three-inone composite wave-plate through mathematical derivation, and propose a method to analyze and extract the misalignment errors of the composite wave-plate. Obvious oscillations have been observed in the equivalent fast axis azimuth of the composite wave-plate through simulations, and these oscillations can be assigned to the angular misalignment errors between the individual plates of the composite wave-plate. The waveforms and amplitudes of the oscillations in the equivalent fast axis azimuth show high sensitivity to angular misalignment errors. Conversely, angular misalignment errors can be accurately extracted from the oscillations in the equivalent fast axis of the composite wave-plate. It is expected that the proposed method for analysis and extraction of misalignment errors can be used to minimize angular misalignment errors and to improve the alignment procedure of the composite wave-plate.

Real-time measurement of the retardation of the quarter-wave plate (QWP) using a Wollaston prism is presented. The collimated beam passes through a circular polarizer, the quarter-wave plate to be measured, a standard quarter-wave plate and then is split by a Wollaston prism. Two sub-beams are detected by a bi-cell detector. From two detection signals, the retardation of the QWP is obtained in real time and is independent of the fast axis azimuth of QWP. At the same time, the method is easy to expand to measure the retardation of the QWP used in deep ultraviolet band and the retardation distribution of the QWP. In experiments, the average and the standard deviation of the retardation of quarter-wave plate are respectively 89.5o and 0.25o. The usefulness of the method is verified.

A method for simultaneous measurement of the retardance and the fast axis angle of quarter-wave plate using one photoelastic modulator is presented. A laser beam passes through a polarizer, a photoelastic modulator, the quarter-wave plate to be measured, and an analyzer to be detected. Before and after the quarter-wave plate is rotated 45° at any initial fast axis direction, two detection signals are obtained to resolve simultaneously the retardance and the fast axis angle. In experiments, a quarter-wave plate was measured with fast axis angles from −89° to 90°. The average and the standard deviation of the retardances at different fast axis directions are respectively 89.50° and 0.17°. The maximum measurement deviation of the fast axis angle is 0.5°. The usefulness of the method is verified.

We report on the enhanced pulse compression due to the interaction of positive third-order dispersion and cross-phase-modulation effects in birefringent fibres. Polarization soliton compression along the slow axis can be enhanced in birefringent fibres with positive third-order dispersion, and the polarization soliton compression along the fast axis can be enhanced in fibres with negative third-order dispersion. Moreover, the third-order dispersion parameter can be optimized to obtain the optimal pulse compression.

In the steel industry the roll grinding machine has become important for maintenance. The rolls always have surface or shape errors after plastically deforming steel slabs to the steel plate. This error affects the manufacturing quality of the steel plate manufacturing process. There are many parameters for the manufacture of the roll grinding machine, such as speed of roll, speed of grinding wheel and speed of moving horizontally etc. The objective of this work is to reduce the surface error of the roll by using a helical path method. One of the important problems with the roll grinding machine is the coordinated control of the spindle axis roll speed and the z-axis speed; a lower roll speed and fast axis movement will make a roll curve error. To reduce this error a helical path was used. The helical path was used for the C-Axis (C-axis converted from the spindle axis). The results were analyzed using a mathematical model to compare the effects of the conventional method and the helical path method. It was found that the helical path method reduced the error by about 7.8 %.

Optical polarimetry for monitoring glucose concentration in the aqueous humor of the eye as a potential noninvasive means of assessing blood glucose has promise, but the realization of such an approach has been limited by noise from time-varying corneal birefringence due to motion artifact. Modeling the corneal birefringence of the eye is critically important toward understanding the overall effect of this noise source compared to other changes in the signal, and can aid in design of the polarimetric system. To this end, an eye model is introduced in this work that includes spatially varying birefringence properties of the cornea. The degree of birefringence and the fast axis orientation is calculated as a function of beam position on the anterior chamber. It is shown that the minimum change in polarization vector orientation occurs for beam position near the midpoint between the corneal apex and limbus. In addition, the relative wavelength independence of motion artifact is shown in the same region. The direct consequence of these findings are that a multiwavelength polarimetric system can potentially be utilized to eliminate the effect of time-varying corneal birefringence, and that eye coupling is optimal at the midpoint between the apex and limbus.

A study of photoinduced birefringence in bow-tie (stress-induced) high-birefringence (Hi-Bi) and low-birefringence (Lo-Bi) germanosilicate optical fibers is conducted by using 532-nm light. The study reveals that Hi-Bi fibers are insensitive to light polarized along the fast axis, in contrast to Lo-Bi fibers, which are photosensitive along both axes. The induced birefringence in Lo-Bi fibers is reversible, whereas the change in Hi-Bi fibers is permanent. The sign of the induced birefringence is established experimentally for the first time to our knowledge, and the significance of the results to models based on stress and/or glass defects is briefly discussed.

In a recent study we reported on the gradient index (GRIN) lens Stokes polarimeter (GLP) [Opt. Lett.39, 2656 (2014)10.1364/OL.39.002656OPLEDP0146-9592]. With a simple architecture, this polarimeter can measure the state of polarization in a single shot. In this article, we present further studies for improving the performance of the GLP. Detailed discussions are presented on the optimization process of the GLP based on different choices of data from the CCD images. It is pointed out that many optimization techniques, although developed for other types of Stokes polarimeters, can also be applied to the GLP because the GRIN lens can traverse all possible retardance and fast axis modulations.

We exploit the birefringence of cellophane to convert a linearly polarised Gaussian beam into either a radially or azimuthally polarised beam. For that, we fabricated a low-cost polarisation mask consisting of four segments of cellophane. The fast axis of each segment is oriented appropriately in order to rotate the polarisation of the incident linearly polarised beam as desired. To ensure the correct operation of the polarisation mask, we tested the polarisation state of the generated beam by measuring the spatial distribution of the Stokes parameters. Such a device is very cost efficient and allows for the generation of cylindrical vector beams of high quality.

We propose a new criterion for mask birefringence in polarized illumination. Mask birefringence is one of the critical properties of polarized illumination, because the illumination polarization is disturbed by the birefringence of a mask substrate. From this point of view, the allowable mask birefringence has already been analyzed. In these analyses, only the absolute values of birefringence have been specified. As has been pointed out, the mask is a rotation retarder for the polarized illumination. Therefore, the angle of the fast axis of mask birefringence also affects the state of polarization. The new criterion of mask birefringence which we propose here adopts the angle of fast axis as well as the absolute value of birefringence. This new criterion correlates well with the printed critical dimensions (CDs). To demonstrate this, printed CDs were calculated as a function of birefringence. A lithography simulator was used to verify the fit of the new criterion. In this simulation, experimentally measured absolute values of birefringence and the angle of fast axis were used. The simulation showed that there was poor correlation between printed CDs and the absolute values of birefringence. On the other hand, the new criterion exhibited a good correlation with the printed CDs. This difference is attributed to the effect of the angle of fast axis.

A novel method used for the enhancement of the accuracy of the measurement of the retardance of a quarter-wave plate employing two polaroids and a prism is reported under the condition of knowing the direction of the fast axis of the plate. The theoretical analysis of the principle and the uncertainty formula are given. An application example is also demonstrated. The measured result of the example is verified with an experiment. The main advantages of this method include the accuracy enhancement, simple measuring setup and easy operation.

A new design for the vertical waveguide structure of (AIGaIn)(AsSb)-based diode lasers is presented. The active layers of all investigated samples consist of compressively strained 10 nm wide Ga/sub 0.64/In/sub 0.36/As/sub 0.10/Sb/sub 0.90/-QWs, separated by 20 nm wide lattice matched Al/sub 0.29/Ga/sub 0.71/As/sub 0.02/Sb/sub 0.98/ barriers. The emission wavelength is 2.3 /spl mu/m at room temperature. This new quantum-well diode laser design exhibits reduced beam divergence in the fast axis, while the laser performance is maintained compared to a standard large divergence waveguide design. This strong decrease in the fast axis divergence drastically increases the fiber coupling efficiency of GaSb-based diode lasers.

The effect of changing corneal birefringence, due to motion artifact, remains a major obstacle to the development of an accurate non-invasive polarimetric glucose sensor for patients with diabetes mellitus. Consequently, there is still a need to characterize fully, and to quantify the relative changes in corneal birefringence to facilitate the optimization of detection algorithms, enabling in vivo accuracy within 10mg/dl. In this paper, we present preliminary results, utilizing a Mueller matrix imaging technique, that demonstrates notable relative changes in the apparent retardance and in the apparent fast axis location of rabbit cornea.