Abstract:
A spectrometer comprises a plurality of isolated optical channels comprising a plurality of isolated optical paths. The isolated optical paths decrease cross-talk among the optical paths and allow the spectrometer to have a decreased length with increased resolution. In many embodiments, the isolated optical paths comprise isolated parallel optical paths that allow the length of the device to be decreased substantially. In many embodiments, each isolated optical path extends from a filter of a filter array, through a lens of a lens array, through a channel of a support array, to a region of a sensor array. Each region of the sensor array comprises a plurality of sensor elements in which a location of the sensor element corresponds to the wavelength of light received based on an angle of light received at the location, the focal length of the lens and the central wavelength of the filter.
Abstract:
A spectrometer configurable for field analyses of chemical properties of a material is provided. The spectrometer includes: at least one sensor adapted for providing Fourier transform infrared spectroscopy (FTIR) surveillance and at least another sensor for providing Raman spectroscopy surveillance. The spectrometer can be provided with a user accessible instruction set for modifying a sampling configuration of the spectrometer. A method of determining the most likely composition of a sample by at least two technologies using the spectrometer is also provided.
Abstract:
A device for tunable optical filter includes a substrate, one or more piezos, a bottom mirror, and a top mirror. The one or more piezos are placed on the substrate. The one or more piezos have a piezo thickness. The bottom mirror is placed on the substrate. The bottom mirror has a bottom mirror thickness greater than the piezo thickness. The top mirror is placed on the bottom mirror. The top mirror is attached to the one or more piezos.
Abstract:
Apparatuses and method for real-time measuring ultrashort pulse shape and pulse width. Transient-grating effect on a transparent optical medium is used to generate a reference beam. A black plate with four equal-sized holes divides the incoming laser beam into four beams, one of which is attenuated and introduced an appropriate time delay relative to the other three. The four laser beams pass through a concave mirror and are focused onto a nonlinear transparent optical medium. The three beams without attenuation are used to generate a transient-grating light in the transparent medium. The transient-grating light is collinear and overlapped with the fourth attenuated beam. According to the third-order nonlinear effect, the transient-grating light has a broader spectral bandwidth and more smooth spectrum phase with respect to the incident laser. By measuring the spectral interference, the spectrum and spectral phase may be retrieved by spectral interferometry.
Abstract:
Current apparatuses and methods for analysis of spectroscopic optical coherence tomography (SOCT) signals suffer from an inherent tradeoff between time (depth) and frequency (wavelength) resolution. In one non-limiting embodiment, multiple or dual window (DW) apparatuses and methods for reconstructing time-frequency distributions (TFDs) that applies two windows that independently determine the optical and temporal resolution is provided. For example, optical resolution is provided. For example, optical resolution may relate to scattering information about a sample, and temporal resolution may be related to absorption or depth related information. The effectiveness of the apparatuses and methods is demonstrated in simulations and in processing of measured OCT signals that contain fields which vary in time and frequency. The DW technique may yield TFDs that maintain high spectral and temporal resolution and are free from the artifacts and limitations commonly observed with other processing methods.
Abstract:
A method for determining optical properties of a corneal region. The method includes the steps of obtaining a combined tear film aqueous layer plus lipid layer thickness; obtaining a tear film lipid layer thickness; subtracting the tear film lipid layer thickness from the combined tear film aqueous layer plus lipid layer thickness to obtain a tear film aqueous layer thickness; and determining a corneal layer refractive index based on the tear film lipid layer thickness and the tear film aqueous layer thickness.
Abstract:
A spectrometer comprises a plurality of isolated optical channels comprising a plurality of isolated optical paths. The isolated optical paths decrease cross-talk among the optical paths and allow the spectrometer to have a decreased length with increased resolution. In many embodiments, the isolated optical paths comprise isolated parallel optical paths that allow the length of the device to be decreased substantially. In many embodiments, each isolated optical path extends from a filter of a filter array, through a lens of a lens array, through a channel of a support array, to a region of a sensor array. Each region of the sensor array comprises a plurality of sensor elements in which a location of the sensor element corresponds to the wavelength of light received based on an angle of light received at the location, the focal length of the lens and the central wavelength of the filter.
Abstract:
A optical module includes, a wavelength variable interference filter which include reflection films opposite to each other and an electrostatic actuator portion including a first electrostatic actuator and a second electrostatic actuator and changing a gap between the reflection films, and a voltage control portion which controls voltage which is applied to the electrostatic actuator portion, the voltage control portion includes, a bias driving portion which applies bias voltage to the first electrostatic actuator, a gap detector, and a feedback control portion which applies feedback voltage corresponding to a detected gap amount to the second electrostatic actuator.
Abstract:
A wavelength spectroscopy device includes, on a substrate, a filter cell CF constituted by two mirrors separated by a spacer membrane, the filter cell being made up of a plurality of interference filters. Furthermore, the device also includes an emission cell CE having a plurality of emission sources, each of the sources being associated with one of the interference filters.
Abstract:
An optical fiber environmental detection system comprising an interferometer, a broadband light source and a detector is disclosed. The interferometer further comprises a thin core fiber, a first single mode fiber and a second single mode fiber; wherein the thin core fiber is coupled to the first and second single mode fiber via a first junction and a second junction respectively. When an emission light reaches the first junction, high-order cladding modes will be excited. The excited cladding modes will interfere with the core mode at the second junction. The interferences determine the intensity maximum or minimum of the received signal. When there is an ambient environmental change, a shift of the received signal would be induced. According to the shift, environmental change, for instance ambient temperature, could be determined.