Disclosed are an apparatus for measuring a displacement using a fiber Bragg grating sensor, which is applied to a strain sensor using the fiber Bragg grating sensor, and a method of controlling sensitivity and durability of the same. The apparatus includes: a case forming an external appearance; third and fourth optical fibers having mutually different numbers of strands and installed in the case while being spaced apart from each other by a predetermined interval; and a connection unit installed between the third and fourth optical fibers and fixed at a predetermined position by tension applied to the third and fourth optical fibers, wherein the fiber Bragg grating sensor is installed to one selected from the pair of optical fibers having mutually different numbers of strands, so that measurement sensitivity and durability are controllable.

According to one implementation an assembly is provided that facilitates a coupling of one or more light diffusing optical fibers to one or more light emitting diodes. According to one implementation the assembly includes a light emitting diode positioned inside a cavity of a frame that is equipped with means to directly or indirectly electrically couple the anode and cathode of the light emitting diode to a printed circuit board. A proximal end portion of the light diffusing optical fiber is supported inside a through opening of a lid positioned over a front side of the frame. The light diffusing optical fiber includes a core that is surround by a cladding. According to some implementations the proximal end of the light diffusing optical fiber is butt-coupled to the light emitting diode with there being no gap between the proximal end of the fiber and the light emitting side of the light emitting diode.

Systems and methods are described, and one method includes passing an optical beam through a volume of the gas to a reception surface, applying spectroanalysis to the optical beam received at the reception surface, and determining from the spectroanalysis whether a liquid is carried by the volume of the gas.

A guiding system (1, 101) for guiding the insertion of a needle (2) and a catheter (6) for medical use in a biological tissue, the guiding system (1, 101) comprising: the needle (2) the catheter (6) inserted into the needle (2); an optical fiber (8) provided with at least one optical sensor (10) and inserted into the catheter (6), a first blocking device (12, 112) for firmly blocking the catheter (6) inside the needle (2).

A surgical robotic user input apparatus has a fiber optic cable with a handheld user input device attached at one end, and a connector attached at another end. Multiple intrinsic sensors, such as fiber Bragg grating sensors, are in the fiber optic cable. The intrinsic sensors are used to detect a pose of the handheld user input device. Other embodiments are also described and claimed.

Multiplexed reflection and transmission gratings, and methods of their manufacture, are provided that improve uniformity with laser light, that is, reduced banding and other illumination artifacts occurring in waveguides. The mechanism for this can be the multiple reflections between the waveguide reflecting surfaces and the reflection hologram, which promote illumination averaging as beam propagation processes within a waveguide. In some gratings, a beam splitter layer overlapping the multiplexed gratings can be provided for the purposes of reducing banding in a laser-illuminated waveguide. The beam splitter can be provided by one or more dielectric layers. The beamsplitter can have sensitivity to one polarization. The beamsplitter can be sensitive to S-polarization. The beam splitter can be an anti-reflection coating optimized for normal incidence that becomes reflective at high TIR angles when immersed in glass or plastic.

A number of variations may include a product comprising: at least one sensor comprising an optical fiber comprising a first end comprising a semiconductor material, a second end, and a longitudinal midsection comprising a grating, wherein the sensor is constructed and arranged to provide measurements that derive both state of charge and temperature of an electrochemical device simultaneously.

An optical guidewire system employs an optical guidewire (10), an optical guidewire controller (12), a guide interface (13) and an optical connector (15). The optical guidewire (10) is for advancing a catheter (20) to a target region relative to a distal end of the optical guidewire (10), wherein the optical guidewire (10) includes one or more guidewire fiber cores (11) for generating an encoded optical signal (16) indicative of a shape of the optical guidewire (10). The optical guidewire controller (12) is responsive to the encoded optical signal (16) for reconstructing the shape of the optical guidewire (10). The guidewire interface (13) includes one or more interface fiber core(s) (14) optically coupled to the optical guidewire controller (12). The optical connector (15) facilitates a connection, disconnection and reconnection of the optical guidewire (10) to the guidewire interface (13) that enables a backloading the catheter (20) on the optical guidewire (10).

There is provided a projection display device comprising: a light source, an SBG device comprising a multiplicity of separately SBG elements sandwich between transparent substrate to which transparent electrodes have been applied. The substrates function as a light guide. A least one transparent electrode comprises plurality of independently switchable transparent electrodes elements, each electrode element substantially overlaying a unique SBG element. Each SBG element encodes image information to be projected on an image surface. Light coupled into the light guide, undergoes total internal reflection until diffracted out to the light guide by an activated SBG element. The SBG diffracts light out of the light guide to form an image region on an image surface when subjected to an applied voltage via said transparent electrodes.

An optical fiber sensor includes: a central core disposed at a center of an optical fiber; and an outer peripheral core that spirally surrounds the central core. The effective refractive index n.sub.e2 of the outer peripheral core is lower than the effective refractive index n.sub.e1 of the central core. A ratio between the effective refractive index n.sub.e2 and the effective refractive index n.sub.e1 matches a ratio between an optical path length of the central core and an optical path length of the outer peripheral core.