Class / Patent application number | Description | Number of patent applications / Date published |
372096000 | Distributed feedback | 13 |
20080205476 | HIGH EFFICIENCY PARTIAL DISTRIBUTED FEEDBACK (p-DFB) LASER - A second-order multi-mode partial distributed feedback (p-DFB) laser having increased electrical-to-optical power conversion efficiency, stabilized wavelength and narrowed emission linewidth. The laser includes an abbreviated grating housed in the laser cavity that is separated from both the front-end and the back-end of the laser facets. | 08-28-2008 |
20090010298 | TWO-DIMENSIONAL PHOTONIC CRYSTAL SURFACE-EMITTING LASER - A two-dimensional photonic crystal formed by arranging in a lattice pattern a medium having a refractive index different from that of a medium layer formed near an active layer. The two-dimensional photonic crystal includes a distributed-feedback control photonic crystal in which a light propagating through the active layer as a core is subjected to a two-dimensional distributed feedback within a plane of the active layer, and the light is not radiated in a direction normal to the plane of the active layer, and a surface-emission control photonic crystal in which the light is radiated in the direction normal to the plane of the active layer, which are superimposed with each other. | 01-08-2009 |
20090034576 | LINEWIDTH-NARROWED EXCIMER LASER CAVITY - A double-grating excimer laser cavity is disclosed which includes a first multilayer dielectric diffraction grating comprised of a dielectric stack having a plurality of continuous layers with alternating high and low refractive indices, and a nonmetallic diffraction grating disposed on the top layer of the plurality of layers. The nonmetallic diffraction grating is a single pair of layers made of a low refractive index dielectric material and a high refractive index dielectric material. Grooves extend through the pair of layers. The diffraction grating has a diffraction efficiency of greater than 85% at the laser emission wavelength. The laser produces a laser output beam with a narrow spectral linewidth which is suitable, in particular, for lithography applications. | 02-05-2009 |
20090147818 | ENHANCED SURFACE-EMITTING PHOTONIC DEVICE - A surface-emitting photonic device including a structure disposed therein to enhance a performance thereof. The structure includes a two dimensionally periodic second order distributed feedback device (DFB) to emit diffraction limited outcoupled laser light having a predetermined wavelength along a propagation direction that is substantially normal to a plane of the DFB, and a first order distributed Bragg reflector (DBR) coplanar with, adjacent to and surrounding the DFB, a geometry of the DBR being selected such that a bandgap of the DBR is maximized and centered around the predetermined wavelength of the emitted light, a substrate, and either an optical gain layer, or a semi-conductor quantum well laser disposed within the substrate. | 06-11-2009 |
20100002743 | LASER FOCUSING THROUGH TURBULENT MEDIUM - Methods and systems for performing target-in-the-loop, real-time laser beam phase aberration compensation through a turbulent atmosphere are disclosed. The methods and systems can distinguish between phase aberration contributions from atmospheric turbulence-induced phase aberration and target-induced phase aberration caused by target surface roughness. Selected components of incoming light can be used to define a reversed wavefront and a reverse direction of propagation such that a laser beam returned to a target tends to be concentrated upon a desired region of a target. In this manner, applications such as laser target designation, tracking, pointing, active imaging, and directed energy systems are better facilitated. | 01-07-2010 |
20100046572 | Photonic-Crystal-Based Photon Extractor for High-Yield Optical Microsources - The invention relates to a photon extractor comprising a photonic-crystal-based membrane having a plane defined by two perpendicular directions, comprising an array of features and a cavity devoid of features, from which photons may be extracted, characterized in that the membrane comprises at least one region close to the cavity, said region having features distributed with a double periodicity (a | 02-25-2010 |
20100135350 | Wavelength stabilized light emitter and system for protecting emitter from backreflected light - A gain module, operative to output a laser light coupled into a laser system, is structured with at least one gain element radiating the laser light and a spectrally-selective element. The spectrally-selective element includes a slab of photosensitive material and two parallel feedback and isolating Bragg mirrors recorded in the slab. The feedback Bragg mirror is operative to provide a wavelength-dependent feedback so as to cause the laser chip to generate the laser light at the resonance wavelength of the feedback Bragg mirror. The isolating Bragg mirror is automatically adjusted to retroreflect a backreflected signal light, which is generated by the laser system at a signal wavelength different from the resonance wavelength, upon positioning the feedback mirror orthogonally to the laser light. | 06-03-2010 |
20120269224 | DISTRIBUTED FEEDBACK SURFACE EMITTING LASER - A photonic crystal surface emitting laser array reduces the occurrence of reflected feedback light while also reducing input of leaking light. The photonic crystal surface emitting laser array includes a plurality of first photonic crystal regions that cause laser oscillation, a second photonic crystal region that causes light diffraction to occur in an out-of-plane direction, and a light absorber that is provided above the second photonic crystal region and that absorbs light having a wavelength λ. A radiation coefficient of each first photonic crystal region is smaller than a radiation coefficient of the second photonic crystal region. | 10-25-2012 |
20130094532 | Opto-Electronic Oscillator And Method - An opto-electronic oscillator circuit, including: an opto-electronic circuit loop including an optical modulator that receives a first electrical signal and produces an optical output signal coupled with an optical resonator, a photodetector circuit optically coupled with the optical resonator, and a phase shifter coupled with the photodetector circuit for producing a phase shifted output signal that is fed back as the first electrical signal; an optical loop comprising the optical coupling of the optical resonator with the photodetector; and an electrical feedback circuit loop for coupling the first electrical signal with the photodetector circuit. | 04-18-2013 |
20140126603 | SPATIALLY DISTRIBUTED LASER RESONATOR - A distributed resonator laser system using retro-reflecting elements, in which spatially separated retroreflecting elements define respectively a power transmitting and a power receiving unit. The retroreflectors have no point of inversion, so that an incident beam is reflected back along a path essentially coincident with that of the incident beam. This enables the distributed laser to operate with the beams in a co-linear mode, instead of the ring mode described in the prior art. This feature allows the simple inclusion of elements having optical power within the distributed cavity, enabling such functions as focusing/defocusing, increasing the field of view of the system, and changing the Rayleigh length of the beam. The optical system can advantageously be constructed as a pupil imaging system, with the advantage that optical components, such as the gain medium or a photo-voltaic converter, can be positioned at such a pupil without physical limitations. | 05-08-2014 |
20150023382 | TUNABLE DBR LASER AND A METHOD OF OPERATING A TUNABLE DBR LASER - A tunable DBR laser including: an amplifier section, a part-reflecting optical output, a connection section connected to the amplifier section, and at least two wavelength-selective reflectors optically coupled to the amplifier section via the connection section. The connection section includes at least one MMI coupler and several waveguides, so that different optical paths lead from the amplifier section to the wavelength-selective reflectors and each of the different optical paths leads through the at least one MMI coupler and through one of the waveguides. The wavelength-selective reflectors differ from one another by having different reflection spectra and each of the wavelength-selective reflectors is connected to one of several outputs of the at least one MMI coupler. By activating a phase shifter, arranged in a course of at least one of the waveguides, the DBR laser can be switched between different resonators. | 01-22-2015 |
20150043607 | DISTRIBUTED FEEDBACK (DFB) LASER WITH SLAB WAVEGUIDE - A distributed feedback (DFB) laser includes a substrate of a compound semiconductor material, and quantum-well (QW) active layer(s) overlying the substrate. A p-doped cladding layer including the compound semiconductor material is on one side of the active layer and an n-doped cladding layer is on the other side. A grating is in one of the cladding layers configured to select an operating wavelength for the DFB laser. A waveguide structure in the n-doped cladding layer includes a waveguide layer of a first composition compositionally different from the compound semiconductor material having an optical thickness of 0.7 to 1.5 of the guided wavelength. The waveguide structure can further include a hetero-waveguide stack including a plurality of alternating compositional layers beyond the waveguide layer each having a thickness between one quarter and one half the guided wavelength alternating the compound semiconductor material with a second composition defining a composition wavelength. | 02-12-2015 |
20160087391 | SPATIALLY DISTRIBUTED LASER RESONATOR - A distributed resonator laser system using retro-reflecting elements, in which spatially separated retroreflecting elements define respectively a power transmitting and a power receiving unit. The retroreflectors have no point of inversion, so that an incident beam is reflected back along a path essentially coincident with that of the incident beam. This enables the distributed laser to operate with the beams in a co-linear mode, instead of the ring mode described in the prior art. This feature allows the simple inclusion of elements having optical power within the distributed cavity, enabling such functions as focusing/defocusing, increasing the field of view of the system, and changing the Rayleigh length of the beam. The optical system can advantageously be constructed as a pupil imaging system, with the advantage that optical components, such as the gain medium or a photo-voltaic converter, can be positioned at such a pupil without physical limitations. | 03-24-2016 |