An apparatuses relating generally to a test wafer, processing chambers, and method relating generally to monitoring or calibrating a processing chamber, are described. In one such an apparatus for a test wafer, there is a platform. An optical fiber with Fiber Bragg Grating sensors is located over the platform. A layer of material is located over the platform and over the optical fiber.

Sensor shaped to have a frequency response that has less spectral fading than a sensor with a rectangular wrapping pattern, and methods for making such sensors, are disclosed. One such method includes selecting a wrapping pattern comprising multiple layers in which a top layer has a different length than a bottom layer and where the bottom layer is adjacent a mandrel. The method further includes wrapping optical fiber around the mandrel according to the wrapping pattern.

A lighting unit includes a single core optical fiber, a light converter, and an exit end. The single core optical fiber includes an incident end and a distal end, and is configured to guide primary light, which is a laser light incident on the incident end, to the distal end. The light converter is formed inside the optical fiber, and is configured to receive the primary light guided by the optical fiber, convert optical properties of at least part of the received primary light and generate secondary light. The exit end is arranged at the distal end of the optical fiber, and is configured to emit the secondary light externally as illumination light.

Fiber Bragg grating interrogation and sensing used for strain and temperature measurements. A simple, broadband light source is used to interrogate one or more fiber Bragg grating (FBG). Specifically, a packaged LED is coupled to fiber, the light therefrom is reflected off a uniform FBG. The reflected light is subsequently analyzed using a filter and a plurality of Si photodetectors. In particular, the filter is a chirped FBG or an optically coated filter, in accordance with some embodiments. Measurement analysis is performed by ratio of intensities at the plurality of detectors, at least in part.

A reflector includes a gain fiber and a periodic refraction structure unit. The gain fiber has a core doped with a rare earth element. The periodic refraction structure unit includes a high-refractive-index region that has a predetermined width, that is formed at a predetermined spacing along an optical axis direction of the gain fiber, that is formed across an entire section of the core that is orthogonal to the optical axis of the core, and that has a first refractive index, and a low-refractive-index region that is formed adjacent to the high-refractive-index region, that has a width equal to the predetermined spacing, and that has a second refractive index lower than the first refractive index. A width d.sub.i of an i.sup.th periodic structure of refractive index in the periodic refraction structure unit is given by the equation d.sub.i=H.sub.i.Math.(/(2.Math.n.sub.i))+/(4.Math.n.sub.i).

A system and method for detecting dynamic strain of a housing. The system includes an optical fiber linearly affixed along a surface of a length of the housing and an interrogator comprising a laser source and a photodetector. The optical fiber comprises at least one pair of fiber Bragg gratings (FBGs) tuned to reflect substantially identical wavelengths with a segment of the optical fiber extending between the FBGs. The segment of the optical fiber is linearly affixed along the surface of the housing. The interrogator is configured to perform interferometry by shining laser light along the optical fiber and detecting light reflected by the FBGs. The interrogator outputs dynamic strain measurements based on interferometry performed on the reflected light.

An optoelectronic apparatus includes a dual folding mirror, which is mounted on a carrier substrate and includes first and second reflecting surfaces disposed at opposite angles relative to a normal to the carrier substrate. First and second sensing devices are disposed respectively in proximity to the first and second reflecting surfaces. Each sensing device includes a planar substrate disposed on the carrier substrate and an array of sensing cells disposed on the planar substrate and including respective edge couplers disposed along the edge of the planar substrate so as to couple optical radiation between the sensing cells and the respective reflecting surface.

In this light source device, in order to reduce the size thereof and reduce the line width, a first optical fiber 12 is optically coupled to a light source 11. Through the first optical fiber 12, light that has exited from the light source 11 is let into a second optical fiber 14 to be guided thereby. An optical isolator 13 is inserted between the first optical fiber 12 and the second optical fiber 14. An optical fiber that readily generates back-scattering is used for the first optical fiber 12. As light that has back-scattered in the first optical fiber 12 returns to the light source 11, and by constituting a long resonator, the line width of the output light can be reduced.

A distributed device for the detection of a substance is disclosed, comprising: a distributed optical excitation source (21) including a first optical fiber (22) having a plurality of extraction regions (24), each extraction region (24) being adapted to extract part of the light carried by the first optical fiber (22) from said fiber; and a distributed acoustic sensor (25) including a second optical fiber (26).

In the wavelength selective switch provided in the present invention, at least one optical element is successively arranged in the wavelength selective switch according to a sequence of processing optical signals. The at least one optical element receives a service optical signal from a service laser, receives a monitoring optical signal from a monitoring laser, and performs same optical signal processing on the service optical signal and the monitoring optical signal according to a processing function of the at least one optical element, where a wavelength of the service optical signal and a wavelength of the monitoring optical signal are different. A service optical signal processed by the at least one optical element and a monitoring optical signal processed by at least one optical element are output, where the monitoring optical signal processed by the at least one optical element is used for monitoring performance of the wavelength selective switch.