Patent application number | Description | Published |
20080264910 | Process for Fabricating Optical Waveguides - A one step process for fabricating planar optical waveguides comprises using a laser to cut at least two channels in a substantially planar surface of a piece of dielectric material defining a waveguide there between. The shape and size of the resulting guide can be adjusting by selecting an appropriate combination of laser beam spatial profile, of its power and of the exposure time. A combination of heating and writing lasers can also be used to fabricate waveguides in a dielectric substrate, wherein the heating laser heats the substrate with a relatively broad focused spot, the power of the heating laser being controlled to raise the temperature heating the substrate just below the substrate's threshold temperature at which it begins to absorb electro-magnetic radiation, the writing laser, which yields a spot size smaller than the heating laser then melts the substrate within the focal spot of the heating laser. Compare to processes from the prior art, a waveguide fabrication process according to the present invention results in lower cost, faster processing time and applicability to a wider range of materials. The present process is particularly suited for the mass production of inexpensive photonic devices. | 10-30-2008 |
20080267555 | Plasmon-Polariton Refractive-Index Fiber Bio-Sensor with Fiber Bragg Grating - An optical waveguide sensing method and device in which a waveguide layer receives an optical signal and propagates the optical signal in accordance with a predetermined optical waveguide propagation mode. A testing medium surface in communication with the waveguide layer is responsive to a testing medium for modifying at least one characteristic of the propagated optical signal in relation to a given parameter of the testing medium. In this manner, the modified characteristic of the propagated optical signal can be measured in view of determining the given parameter of the testing medium. | 10-30-2008 |
20090231682 | HIGH-POWER FIBER AMPLIFIER - Fiber light amplifiers adapted for high power application are provided. In embodiments of the invention, the light signal to be amplified is coupled to a cladding mode of an active waveguide region which is cladding doped. The amplified light is coupled to an output fiber have waveguiding properties matching those of the active cladding of the active waveguide region. In other embodiments, two or more amplifying stages are provided coupled by a wavelength selective loss element which couples the Stokes wave co-propagating with the signal to be amplified out of the signal guiding mode prior to the onset of SRS. | 09-17-2009 |
20090260501 | MULTI-MODE OPTICAL FIBER SENSOR - There is described an optical fiber sensor for sensing one of vibration, temperature, and strain, comprising: a laser source; a first single mode optical fiber having a first end and a second end, the first end connected to the laser source for receiving and propagating light from the laser source; a multimode optical fiber having a first end and a second end, the first end connected to the second end of the first single mode optical fiber for receiving the light and thereby exciting a plurality of modes of the multimode optical fiber, the multimode optical fiber being stretched at an out of band frequency and operated at a point at which an output is a linear function of a displacement of the multimode fiber; and a sampling photo-detector module connected to the second end of the multimode optical fiber for spatially filtering an output of the multimode fiber to obtain a spatially filtered interference pattern, and for detecting a variation of the spatially filtered interference pattern when one of the vibration, temperature, and strain is applied to the multimode optical fiber. | 10-22-2009 |
20100061689 | Process for Fabricating Buried Optical Waveguides Using Laser Ablation - The present invention is concerned with a process for fabricating a buried optical waveguide, comprising providing a multi-layer piece of material having a waveguide core layer, generating a laser beam and producing by ablation at least two trenches by applying the laser beam onto the multi-layer piece of material. The two trenches extend through the multi-layer piece of material including the core layer. Upon the ablation, melted material from the multi-layer piece is produced and the core layer is encapsulated between the two trenches with the melted material to produce the buried optical waveguide in the multi-layer piece of material. The present invention also relates to a buried optical waveguide comprising a multi-layer piece of material having a waveguide core layer, at least two trenches laser ablated through the multi-layer piece of material including the core layer and encapsulating material having melted from the multi-layer piece upon laser ablation and leaked to cover and therefore encapsulate the core layer in the at least two trenches to thereby form the buried optical waveguide. | 03-11-2010 |
20110038034 | QUASI-PHASE-MATCHED WAVELENGTH CONVERTER - There is provided an optical frequency converter comprising: an optical guiding structure having an input and an output, and comprising: a first grating portion adjacent to the input; a second grating portion adjacent to output, and a third grating between the first and second grating portion to form an apodized step-chirped grating extending between the input and the output. Each grating portion comprises a plurality of sections each comprising a plurality of segments. Each segment has a segment width and comprises a poled region having a poled width at least equal to one micron and a reversely poled region. The segment width for all of the grating portions and a duty ratio of the poled width to the segment width are constant within each section. The duty ratio increases within the first grating portion, decreases within the second grating portion, and is constant within the third grating portion. | 02-17-2011 |
20120106893 | GRATING INSCRIBING IN OPTICAL WAVEGUIDES - There is described herein a method and system for inscribing gratings in optical waveguides. The waveguides may be hydrogen-free, germanium-free, low germanium, low hydrogen, and a combination thereof. Such gratings written in hydrogen-free fibers are suitable for sensor applications in which the use of hydrogen for photosensitizing fibers is undesirable owing to their increased sensitivity to nuclear radiation. The grating are formed by at least one pulse having a wavelength comprised between about 203 nm and about 240 nm. The laser source may be a Continuous Wave (CW) laser source or a pulsed laser source generating at least one pulse having a width in the order of nanoseconds (10 | 05-03-2012 |
20120312028 | METHODS FOR LASER COOLING OF FLUORESCENT MATERIALS - Methods for cooling fluorescent material are provided. A first method includes providing a sample of the material having an elongated direction of light propagation, exhibiting fluorescence at a mean fluorescence wavelength and capable of emitting superradiant pulses with a formation delay time. The method then involves generating a pump pulsed laser beam having a wavelength longer than the mean fluorescence wavelength, a pump power at which superradiant pulses are emitted and a pulse duration shorter than the formation delay time. The pulses are directed onto the sample along the direction of light propagation to produce the superradiant pulses in an anti-Stokes process inducing a cooling of the sample. A second laser cooling method includes a combination of a traditional anti-Stokes cooling cycle and an upconversion cooling cycle, wherein the two cooling cycles act cooperatively to cool the sample. | 12-13-2012 |
20150043598 | METHOD FOR GENERATING OPTICAL PULSES AND OPTICAL PULSE GENERATOR - The method generally has the steps of propagating a seed wave in an optical fiber; generating a wave of first order by stimulated Brillouin scattering of the seed wave in the optical fiber, the wave of first order having a frequency spectrally shifted from the seed wave and being backscattered from the seed wave; propagating the seed wave and the wave of first order in a feedback cavity thereby generating a plurality of waves of higher order, each wave of higher order being cascadely generated by the wave of previous order, each wave of higher order being backscattered and having a frequency spectrally shifted from its corresponding wave of previous order and forming a frequency comb with the seed wave and the wave of first order; the frequency comb generating optical pulses; and propagating the generated optical pulses out of the feedback cavity. | 02-12-2015 |