In one embodiment of the invention, a semiconductor optical amplifier (SOA) in a laser ring is chosen to provide low polarization-dependent gain (PDG) and a booster semiconductor optical amplifier, outside of the ring, is chosen to provide high polarization-dependent gain. The use of a semiconductor optical amplifier with low polarization-dependent gain nearly eliminates variations in the polarization state of the light at the output of the laser, but does not eliminate the intra-sweep variations in the polarization state at the output of the laser, which can degrade the performance of the SS-OCT system.

A system for monitoring a building structure is described. The system comprises a laser source which emits an infrared radiation and an interferometric arrangement which divides the radiation into an object beam and a reference beam. The object beam irradiates the building structure and is scattered by it, while the reference beam interferes with the scattered object beam so as to create a hologram of the building. The system also comprises a sensor which detects a sequence of holograms and a processing unit which reconstructs the evolution in time of deformations or displacements of the building by numerically processing the sequence of holograms. The system—being based on digital holography—offers various advantages compared to known monitoring techniques, for example techniques which make use of seismometers (possibility of remote monitoring, substantial space-time continuity of the monitoring, capacity for detecting a wider range of deformations and displacements).

The present invention relates to accurately determining a contour of a depolarizing region.

An image processing apparatus extracts a depolarizing region in a polarization-sensitive tomographic image of a subject's eye, and detects, in a tomographic intensity image of the subject's eye, a region corresponding to the extracted depolarizing region. The tomographic intensity image corresponds to the polarization-sensitive tomographic image,

A method of assessing tissue health comprises the steps of obtaining depth-resolved spectra of a selected area of in vivo tissue, and assessing the health of the selected area based on the depth-resolved structural information of the scatterers. Obtaining depth-resolved spectra of the selected area comprises directing a sample beam towards the selected area at an angle, and receiving an angle-resolved scattered sample beam. The angle-resolved scattered sample beam is cross-correlated with the reference beam to produce an angle-resolved cross-correlated signal about the selected area, which is spectrally dispersed to yield an angle-resolved, spectrally-resolved cross-correlation profile having depth-resolved information about the selected area. The angle-resolved, spectrally-resolved cross-correlation profile is processed to obtain depth-resolved information about scatterers in the selected area.

The tomographic image capturing device of the present invention includes a tomographic image capturing means that scans measurement light on a subject's eye fundus (E) to capture tomographic images of the subject's eye fundus and an image processing means that compresses a picture of the captured tomographic images in a scan direction to generate a new tomographic picture. The tomographic image capturing means performs scan at a second scan pitch (P.sub.L) narrower than a first scan pitch (P.sub.H) to capture the tomographic images of the subject's eye fundus. The image processing means compresses the picture (B11) of the tomographic images captured at the second scan pitch (P.sub.L) in the scan direction to generate the new tomographic picture (B12). The measurement width in the scan direction of the new tomographic picture (B12) is a width of a picture corresponding to a measurement width in the scan direction of a tomographic picture (Bn (n=1 to 10)) obtained by scan at the first scan pitch (P.sub.H).

An optical coherence tomography (OCT) system using partial mirrors is generally described. In an example, the OCT system includes a swept light source. The system further includes an interferometer into which light from the light source is directed and a detector configured to produce an imaging sample signal based on light received from the interferometer. The system also includes a partial mirror disposed over an aperture, wherein the partial mirror is configured to transmit light within a first wavelength range and reflect light within a second wavelength range.

A method of measuring a surface of an optical element and an interferometric measuring device for measuring a surface or profile of the optical element. The optical element having a first surface and a second surface opposite the first surface. The method includes defining at least a first measurement point, a second measurement point and a third measurement point on a measurement surface of the optical element being one of the first surface and the second surface, measuring a first position of the first measurement point by directing a measurement beam from a measurement head onto the first measurement point and by detecting a measurement beam portion reflected at the first measurement point, subsequently measuring at least a second position of the second measurement point and a third position of the third measurement point by directing the measurement beam onto the second measurement point and onto the third measurement point and by detecting a measurement beam portion reflected at the second measurement point and the third measurement point, respectively, and determining at least one of a decenter and a tilt of the measurement surface relative to a reference axis on the basis of at least the first position, the second position and the third position.

A method of measuring a surface of an optical element and an interferometric measuring device for measuring a surface or profile of the optical element. The optical element having a first surface and a second surface opposite the first surface. The method includes defining at least a first measurement point, a second measurement point and a third measurement point on a measurement surface of the optical element being one of the first surface and the second surface, measuring a first position of the first measurement point by directing a measurement beam from a measurement head onto the first measurement point and by detecting a measurement beam portion reflected at the first measurement point, subsequently measuring at least a second position of the second measurement point and a third position of the third measurement point by directing the measurement beam onto the second measurement point and onto the third measurement point and by detecting a measurement beam portion reflected at the second measurement point and the third measurement point, respectively, and determining at least one of a decenter and a tilt of the measurement surface relative to a reference axis on the basis of at least the first position, the second position and the third position.

A mirror unit 2 includes a mirror device 20 including a base 21 and a movable mirror 22, an optical function member 13, and a fixed mirror 16 that is disposed on a side opposite to the mirror device 20 with respect to the optical function member 13. The mirror device 20 is provided with a light passage portion 24 that constitutes a first portion of an optical path between the beam splitter unit 3 and the fixed mirror 16. The optical function member 13 is provided with a light transmitting portion 14 that constitutes a second portion of the optical path between the beam splitter unit 3 and the fixed mirror 16. A second surface 21b of the base 21 and a third surface 13a of the optical function member 13 are joined to each other.

The present disclosure provides improved systems and methods for automated cell identification/classification. More particularly, the present disclosure provides advantageous systems and methods for automated cell identification/classification using shearing interferometry with a digital holographic microscope. The present disclosure provides for a compact, low-cost, and field-portable 3D printed system for automatic cell identification/classification using a common path shearing interferometry with digital holographic microscopy. This system has demonstrated good results for sickle cell disease identification with human blood cells. The present disclosure provides that a robust, low cost cell identification/classification system based on shearing interferometry can be used for accurate cell identification. For example, by combining both the static features of the cell along with information on the cell motility, classification can be performed to determine the type of cell present in addition to the state of the cell (e.g., diseased vs. healthy).