Abstract:
An optical radiation source produced from a disordered semiconductor material, such as black silicon, is provided. The optical radiation source includes a semiconductor substrate, a disordered semiconductor structure etched in the semiconductor substrate and a heating element disposed proximal to the disordered semiconductor structure and configured to heat the disordered semiconductor structure to a temperature at which the disordered semiconductor structure emits thermal infrared radiation.
Abstract:
An optical system includes a tunable semiconductor light emitter that generates an input beam having a wavelength shorter than about 2.5 microns, an optical isolator coupled to the emitter and configured to block reflected light into the emitter, an optical amplifier receiving the input beam and outputting an intermediate beam, and optical fibers receiving the intermediate beam and forming an output beam. A subsystem includes lenses or mirrors that deliver the output beam to a sample. The subsystem may include an Optical Coherence Tomography (OCT) apparatus having a sample arm and a reference arm, the output beam having a temporal duration greater than approximately 30 picoseconds, a repetition rate between continuous wave and Megahertz or higher, and a time averaged intensity less than approximately 50 MW/cm2. The system may also include a light detection system collecting any of the output beam that reflects or transmits from the sample.
Abstract translation:光学系统包括可调谐半导体光发射器,其产生具有短于约2.5微米的波长的输入光束;光隔离器,耦合到发射器并被配置为阻挡入射发射器的反射光;接收输入光束的光放大器, 中间光束和接收中间光束的光纤并形成输出光束。 子系统包括将输出光束传递到样品的透镜或反射镜。 子系统可以包括具有采样臂和参考臂的光学相干断层扫描(OCT)装置,输出光束具有大于约30皮秒的时间持续时间,连续波和兆赫兹或更高之间的重复频率以及时间平均强度 小于约50MW / cm 2。 该系统还可以包括光检测系统,其收集从样品反射或透射的任何输出光束。
Abstract:
Disclosed is a method for a phase-insensitive single-sampling point (SSP) data collection system. A rotated 90° infrared (IR) THz signal from a step-tunable IR laser is passed though the fast axis of a 90° polarizing rotator. The polarizing rotator and a second IR signal are coupled to free space through an electro-optic phase modulator (EO-PM), where the EO-PM only retards the phase of along the slow-axis. The polarization angle is rotated by 45° to form a beat frequency in each arm. The light is passed through a polarizer aligned with the slow axis of the PM fiber. Lastly, a resultant IR beat signal is fiber coupled back into the system and an erbium doped fiber amplifier (EDFA) in each arm amplifies the IR power prior to pump the THz emitter and detector.
Abstract:
Various implementations of an apparatus for sensing one or more parameters are disclosed herein. The apparatus includes a sweeping wavelength laser configured to generate a sweeping wavelength optical signal; an optical fiber including a Fiber Bragg Grating (FBG) structure configured to sense a parameter, wherein the optical fiber is configured to receive the sweeping wavelength optical signal, wherein the FBG structure is configured to produce a reflected optical signal with a particular wavelength in response to the sweeping wavelength optical signal, and wherein the particular wavelength varies as a function of the parameter; a photo detector configured to generate an electrical signal based on the reflected optical signal; a comparator configured to generate a pulse based on a comparison of the electrical signal to a threshold; and a processor configured to generate an indication of the parameter based on the pulse. The comparator may be configured as a Schmitt trigger.
Abstract:
A method and a system for measuring an optical asynchronous sample signal. The system for measuring an optical asynchronous sampling signal comprises a pulsed optical source capable of emitting two optical pulse sequences with different repetition frequencies, a signal optical path, a reference optical path, and a detection device. Since the optical asynchronous sampling signal can be measured by merely using one pulsed optical source, the complexity and cost of the system are reduced. A multi-frequency optical comb system using the pulsed optical source and a method for implementing the multi-frequency optical comb are further disclosed.
Abstract:
An optical system for use in material processing includes a plurality of semiconductor diodes coupled to a beam combiner to generate a multiplexed optical beam. A cladding pumped fiber amplifier or laser receives the multiplexed optical beam and forms an intermediate beam having at least a first wavelength. An optical element receives the intermediate beam and forms an output beam with an output beam wavelength, wherein the output beam wavelength is at least in part longer than the first wavelength. A subsystem includes lenses or mirrors to deliver a delivered portion of the output beam to a sample. The delivered output beam has a temporal duration greater than about 30 picoseconds, a repetition rate between continuous wave and Megahertz or higher, and a time averaged intensity of less than approximately 50 MW/cm2. The output beam has a time averaged output power of 20 mW or more.
Abstract translation:用于材料处理的光学系统包括耦合到光束组合器的多个半导体二极管以产生多路复用的光束。 包层泵浦光纤放大器或激光器接收复用的光束并形成具有至少第一波长的中间光束。 光学元件接收中间光束并形成具有输出光束波长的输出光束,其中输出光束波长至少部分地长于第一波长。 子系统包括透镜或反射镜,用于将输出光束的传送部分传送到样品。 所输出的输出光束具有大于约30皮秒的时间持续时间,连续波和兆赫兹或更高之间的重复频率以及小于约50MW / cm 2的时间平均强度。 输出光束的时间平均输出功率为20mW以上。
Abstract:
An optical system for use in material processing includes a plurality of semiconductor diodes coupled to a beam combiner to generate a multiplexed optical beam. A cladding pumped fiber amplifier or laser receives the multiplexed optical beam and forms an intermediate beam having at least a first wavelength. An optical element receives the intermediate beam and forms an output beam with an output beam wavelength, wherein the output beam wavelength is at least in part longer than the first wavelength. A subsystem includes lenses or mirrors to deliver a delivered portion of the output beam to a sample. The delivered output beam has a temporal duration greater than about 30 picoseconds, a repetition rate between continuous wave and Megahertz or higher, and a time averaged intensity of less than approximately 50 MW/cm2. The output beam has a time averaged output power of 20 mW or more.
Abstract translation:用于材料处理的光学系统包括耦合到光束组合器的多个半导体二极管以产生多路复用的光束。 包层泵浦光纤放大器或激光器接收复用的光束并形成具有至少第一波长的中间光束。 光学元件接收中间光束并形成具有输出光束波长的输出光束,其中输出光束波长至少部分地长于第一波长。 子系统包括透镜或反射镜,用于将输出光束的传送部分传送到样品。 所输出的输出光束具有大于约30皮秒的时间持续时间,连续波和兆赫兹或更高之间的重复频率以及小于约50MW / cm 2的时间平均强度。 输出光束的时间平均输出功率为20mW以上。
Abstract:
The present invention is directed to systems and methods which utilize a cavity ring-down spectroscopy (CRDS) technique implemented for the measurements of vapor transmission rate. In one embodiment, the vapor content to be measured is contained within an optical cavity. Light is then injected into the cavity up to a threshold level and the delay time of the injected light is measured. When the wavelength of the injected light is resonant with an absorption feature of the vapor the decay time increases linearly as a function of vapor content. In this manner, vapor content causes a longer delay time and thus the amount of vapor passing through the film (film permeation rate) can be determined in real-time.
Abstract:
A Fourier-Transform Infrared (FTIR) spectrometer for operation in the mid- and long-wave infrared region (about 2-15 micron wavelengths) is disclosed. The FTIR spectrometer is composed of IR-transmitting fiber and uses a broadband IR source. A fiber stretcher is provided to provide a path difference between a first path and a second path having a sample associated therewith. Stretching of the fiber provides a path difference sufficient to generate an interferogram that can subsequently be analyzed to obtain information about a sample. A method for use of the apparatus of the invention is also disclosed. The method involves stretching of an IR-transmitting fiber to create a path difference sufficient to generate an interferogram. Various aspects of these features enable the construction of compact, portable spectrometers.
Abstract:
An apparatus and method for obtaining Raman spectra that are suitable for continuous real-time monitoring, utilizing the basic technique of Raman spectroscopy in cooperation with wavelength-selective optical amplification are described. The invention improves the detection sensitivity of conventional Raman spectroscopy by orders of magnitude by providing strong wavelength-selective optical amplification and narrowband detection of the intense driving laser and the weak Raman signal(s), thereby essentially eliminating the driving laser signal from the detector and detection electronics. The invention is effective for both Stokes and anti-Stokes Raman lines, and either where the incident laser wavelength is fixed and the Raman spectrum is recorded by analyzing the output of the fiber amplifier with a spectrometer, or where the detection wavelength is fixed and the Raman spectrum is recorded by tuning the wavelength of the laser.