49results about How to "Effective refractive index" patented technology

Plural p-n junctions are formed in a waveguide such that they have junction interfaces in a normal direction to a surface of a substrate (to an extending direction of the substrate). Accordingly, a doping concentration changes in only a horizontal direction in the substrate, and it is possible to fabricate using the same processes as those for silicon electronic devices and to perform device fabricating at a low cost. Moreover, two or more junction interfaces are formed in the waveguide and thus an occupied area of the waveguide in a refractive index modulation region expands. Therefore, the efficiency of the refractive index modulation can be improved and a low-voltage operation is possible.

An electrode of a light-emitting device of the OLED type adapted for forming with a second electrode, an optical cavity, including at least one layer based on a material of refraction index n1 including a structured face comprising a plurality of recesses filled with a material of refractive index n2 different from n1.

Disclosed is a novel form of particulate precipitated aragonite calcium carbonate and a novel process for producing it.

The present invention relates to an optical device having a nano-structured surface capable of providing a structural color to a normal human viewer, the device made being manufactured in one single material. A plurality of nano-structured protrusions (5) is further arranged with a first periodicity (P1) in a first direction and a second periodicity (P2) in a second direction, the first and second periodicity being chosen so that the optical reflection is dominated by specular reflection. The nano-structured protrusions are optionally arranged with a relative spatial randomness (SR) with respect to the average surface positions. The position, size, and randomness of the protrusions are arranged so as to provide, at least up to a maximum angle of incidence (A_in) with respect to a normal to the surface, an angle-independent substantially homogeneous structural color perception for a normal human viewer, at least up to a maximum observation angle (A_obs) with respect to a normal to the surface.

A solid-state imaging device includes: an imaging area in which light receiving portions are disposed; an interconnect layer disposed on the light receiving portions, the interconnect layer including metal interconnects having openings and first insulating films; inner-layer lenses formed over the interconnect layer in one-to-one relationship with the light receiving portions; a transparent second insulating film formed on the interconnect layer and the inner-layer lenses; top lenses formed on the second insulating film in one-to-one relationship with the light receiving portions, an upper face of each of the top lenses being a convexly curved face; and a transparent film on the top lenses, the transparent film being formed of a material having a refractive index smaller than a refractive index of the top lenses. In this way, a focal point of at least part of incident light can be situated above a semiconductor substrate.

A Q-modulated semiconductor laser comprises an optical gain section and an electro-absorptive modulator section, separated by a vertically etched air gap acting as a partially reflecting mirror. The modulator section is placed inside an anti-resonant Fabry-Perot cavity and acts as the rear reflector of the laser. The change of the absorption coefficient in the modulator section results in a change in the Q-factor of the laser, and consequently the lasing threshold and output power. Different embodiments are disclosed, which involve a distributed feedback (DFB) laser, a Fabry-Perot laser, a distributed Bragg reflector (DBR) laser, or a wavelength switchable multi-cavity laser. The integrated Q-modulated laser has advantages of high speed, high extinction ratio, low wavelength chirp and low cost.

An interferometer includes a waveguide core, and thin film heaters with widths W1 and W2. The thin film heaters are mounted directly above the waveguide core, and operate as two types of different annealing regions. The annealing, which is carried out by supplying current to the thin film heaters, can alter the quality of the cladding, and change the stress applied on the waveguide core, thereby making it possible to control the polarization dependency. Thus changing the width of the thin film heaters and / or the amount of the supply current thereto enables the permanent control of the effective refractive index (birefringence index) independently in the transverse electric polarization mode and the transverse magnetic polarization mode. This enables the transverse electric polarization mode to be adjusted to a phase difference of .lambda. / 2, and the transverse magnetic polarization mode to a phase difference of zero.

A single-mode fiber laser includes a single mode holding, large mode area optical fiber assembly having a large mode area core, a first cladding and a second cladding. The optical fiber assembly has several unique sections including a gain section having a ytterbium-doped core, first and second reflective sections including fiber Bragg gratings that define a lasing cavity, and an absorptive section also having a ytterbium-doped core, the absorptive section having an output end coupled to an input end of said first reflective section. A broad area, multi-mode diode pump source is configured to pump multi-mode light into a tapered input section and cladding-pump the gain section. The gain section absorbs the multi-mode pump light and emits single-mode light. The absorptive section absorbs emissions at the operating wavelength and prevents operating emissions from reflecting back into said pump source.

A tunable resonant grating filter that can reflect optical radiation at a resonant wavelength, the resonant wavelength being selectively variable. The filter includes a diffraction grating, a planar waveguide, and a light transmissive material having a selectively variable refractive index to permit tuning of the filter, the light transmissive material forming a tunable cladding layer for the waveguide, preferably a liquid crystal material. The diffraction grating is placed on the opposite side of the tunable layer with respect to the planar waveguide, thereby making it possible to tailor the grating structural parameters to the desired bandwidth of the filter response without significantly affecting the tunability of the filter. Within the resonant structure, the core layer, i.e., the waveguide, can be placed close to the tunable layer either in direct contact with the tunable layer or with an interposed relatively thin intermediate layer(s) between the core and the tunable layer.

Electro-optic modulator devices and related waveguide components comprising BaTiO3 films.

The present invention provides a method for fast switching of optical properties in photonic crystals using pulsed / modulated free-carrier injection. The results disclosed herein indicate that several types of photonic crystal devices can be designed in which free carriers are used to vary dispersion curves, stop gaps in materials with photonic bandgaps to vary the bandgaps, reflection, transmission, absorption, gain, or phase. The use of pulsed free carrier injection to control the properties of photonic crystals on fast timescales forms the basis for all-optical switching using photonic crystals. Ultrafast switching of the band edge of a two-dimensional silicon photonic crystal is demonstrated near a wavelength of 1.9 μm. Changes in the refractive index are optically induced by injecting free carriers with 800 nm, 300 fs pulses. Band-edge shifts have been induced in silicon photonic crystals of up to 29 nm that occurs on the time-scale of the pump pulse. The present invention also provides a method of producing a virtual or temporary photonic crystal using free carrier injection into pure semiconductors, bulk or thin film, in which the carriers are generated in patterns which create a patterned refractive index contrast used to steer light beams in the semiconductor while it is being pulsed.

A multimode interference device and a method of configuring the same comprises a multimode interference region having a major axis; and a plurality of ports connected to a side portion of the multimode interference region, wherein the side portion is positioned in a direction other than perpendicular to the major axis.

An optical fiber for an optical fiber sensor and a chemical sensor using the same are disclosed. The optical fiber includes a core area, and a suspended cladding area formed around the core area and having at least one cladding hole. The core area has at least one core hole for reducing an effective refractive index of the core area. The optical fiber and the chemical sensor using the same may have improved measurement sensitivity by increasing an evanescent field fraction of existing suspended core fibers.

Disclosed herein is an optical waveguide element that includes a substrate and a waveguide layer formed on the substrate and comprising lithium niobate. The waveguide layer has a slab part having a predetermined thickness and a ridge part protruding from the slab part. The maximum thickness of the slab part is 0.05 times or more and less than 0.4 times a wavelength of a light propagating in the ridge part.

Planar optical waveguide interferometer (15, 25, 35, 45) comprising: a substrate (8, 28, 38, 48); a bimodal waveguide (10, 20, 20′, 30, 40) comprising at least one layer (1, 2, 3) deposited on said substrate (8, 28, 38, 48), said bimodal waveguide (10, 20, 20′, 30, 40) being designed for supporting a zero-order and a first-order transverse propagating modes, said transverse propagating modes having different dispersion; a sensor plate (21, 31, 41, 51) located in a selected area of the upper side of said bimodal waveguide (10, 20, 20′, 30, 40), said sensor plate (21, 31, 41, 51) being designed for receiving a chemical, biological or physical stimulus, said stimulus being capable of changing the effective refractive index of said bimodal waveguide (10, 20, 20′, 30, 40). The bimodal waveguide (10, 20, 20′, 30, 40) comprises confining means (9) designed for confining light in lateral direction, the bimodal waveguide (10, 20, 20′, 30, 40) being thus designed for supporting one lateral mode. Chip, sensor and sensing method comprising a planar optical waveguide interferometer are provided.

A semiconductor optical converter for use principally in an optical communications system or an optical information processing system. The semiconductor optical converter comprises an n-InP clad layer (12), an optical waveguide layer (13), an SI-InP clad layer (14), and an n-InP clad layer (15) formed sequentially on an SI-INP substrate (11), characterized in that a voltage is applied from an electrode (16) connected with the n-InP clad layer (15) and ground electrode (17) connected with the n-InP clad layer (12). The semiconductor optical converter is especially applicable as a semiconductor phase modulator or a semiconductor Mach-Zehnder phase modulator operating at low voltages and having a low waveguide loss.

A tunable Fabry-Perot filter that is less sensitive to angle of incidence is formed by replacing the cavity (air gap) with a partitioned cavity that has an effective refractive index greater than one. The partitioned cavity includes a pair of partitioned cavity dielectric layers formed on the reflectors on either side of the variable air gap. Each of the dielectric layers has an optical thickness that is less than one fourth the shortest wavelength in the tuning range of the filter. The resulting three-layer partitioned cavity has an effective optical thickness substantially equal to an integral multiple (m) of one half the transmitted wavelength within the tuning range of the filter.

Transparent conductors that exhibit minimal scattering, methods for fabricating such transparent conductors, and display devices comprising such transparent conductors are provided. In one exemplary embodiment, a transparent conductor comprises a substrate having an effective refractive index n1, an over layer overlying the substrate and having an effective refractive index n3, and a transparent conductive coating interposed between the substrate and the over layer. The transparent conductive coating comprises a plurality of conductive components and a matrix material that together have an effective refractive index n2 in the range of about √{square root over (n1×n3)}−Δ≦n2≦√{square root over (n1×n3)}+Δ, wherein Δ is an optimization factor within the range of about 0 to about 0.3.

The present invention relates to a process for fabricating light-emitting devices. More particularly, the aim of the invention is to allow the fabrication of light emitters with improved efficiency by using artificial materials, enabling antireflection or high-reflectivity treatments to be carried out.For this purpose, subwavelength structures are etched on one of the ends of an emissive cavity, enabling the external face to be controlled.The invention applies to any light emitter, and therefore notably to lasers and more particularly still to QCLs (quantum cascade lasers).Moreover, the fabrication process according to the invention is preferably a wafer-scale process

The present publication describes a heat-resistant optical layered structure, a manufacturing method for a layered structure, and the use of a layered structure as a detector, emitter, and reflecting surface. The layered structure comprises a reflecting layer, an optical structure on top of the reflecting layer, and preferably shielding layers for shielding the reflecting layer and the optical structure. According to the invention, the optical structure on top of the reflecting layer comprises at least one partially transparent layer, which is optically fitted at a distance to the reflecting layer.

A subject for the invention is to provide a method of refractive index regulation by which the refractive index of an optical polymer molding can be efficiently changed without necessitating a complicated step, such as the step of oxidizing beforehand, and which when used for producing an optical device, imparts excellent transparency thereto. Another subject is to provide a photochemically refractive-index-changing polymer or photochemically refractive-index-changing polymer composition for use in the method. The invention relates to a method of refractive index regulation characterized in that either a photochemically refractive-index-changing polymer which is a polymer of one or more monomers comprising an acrylic vinyl monomer represented by CH2═C(R1)C(═O)O—R2═CH2 (wherein R1 is hydrogen or methyl and R2 is a saturated or unsaturated hydrocarbon group having 1-20 carbon atoms, provided that the monomer may have one or more heteroatoms and halogen atoms in the molecule) as an essential ingredient and which has radial-polymerizable side-chain vinyl groups remaining in the molecule or a composition containing this polymer is irradiated with a radiation, e.g., ultraviolet, to react the vinyl groups and thereby cause a density change so as to result in a refractive-index increase (Δn) through the irradiation of 0.005 or more.

A semiconductor optical converter for use principally in an optical communications system or an optical information processing system.The semiconductor optical converter comprises an n-InP clad layer (12), an optical waveguide layer (13), an SI-InP clad layer (14), and an n-InP clad layer (15) formed sequentially on an SI-InP substrate (11), characterized in that a voltage is applied from an electrode (16) connected with the n-InP clad layer (15) and a ground electrode (17) connected with the n-InP clad layer (12).The semiconductor optical converter is especially applicable as a semiconductor phase modulator or a semiconductor Mach-Zehnder phase modulator operating at low voltages and having a low waveguide loss.

Disclosed herein is an optical waveguide element that includes a substrate and a waveguide layer formed on the substrate and comprising lithium niobate. The waveguide layer has a slab part having a predetermined thickness and a ridge part protruding from the slab part. The maximum thickness of the slab part is 0.05 times or more and less than 0.4 times a wavelength of a light propagating in the ridge part.

A subject for the invention is to provide a method of refractive index regulation by which the refractive index of an optical polymer molding can be efficiently changed without necessitating a complicated step, such as the step of oxidizing beforehand, and which when used for producing an optical device, imparts excellent transparency thereto. Another subject is to provide a photochemically refractive-index-changing polymer or photochemically refractive-index-changing polymer composition for use in the method.The invention relates to a method of refractive index regulation characterized in that either a photochemically refractive-index-changing polymer which is a polymer of one or more monomers comprising an acrylic vinyl monomer represented by CH2═C(R1)C(═O)O—R2═CH2 (wherein R1 is hydrogen or methyl and R2 is a saturated or unsaturated hydrocarbon group having 1-20 carbon atoms, provided that the monomer may have one or more heteroatoms and halogen atoms in the molecule) as an essential ingredient and which has radial-polymerizable side-chain vinyl groups remaining in the molecule or a composition containing this polymer is irradiated with a radiation, e.g., ultraviolet, to react the vinyl groups and thereby cause a density change so as to result in a refractive-index increase (Δn) through the irradiation of 0.005 or more.

Disclosed herein is an optical waveguide element that includes a substrate and a waveguide layer formed on the substrate and comprising lithium niobate. The waveguide layer has a slab part having a predetermined thickness and a ridge part protruding from the slab part. The maximum thickness of the slab part is 0.05 times or more and less than 0.4 times a wavelength of a light propagating in the ridge part.

The present publication describes a heat-resistant optical layered structure, a manufacturing method for a layered structure, and the use of a layered structure as a detector, emitter, and reflecting surface. The layered structure comprises a reflecting layer, an optical structure on top of the reflecting layer, and preferably shielding layers for shielding the reflecting layer and the optical structure. According to the invention, the optical structure on top of the reflecting layer comprises at least one partially transparent layer, which is optically fitted at a distance to the reflecting layer.

Provided is an integrated semiconductor light source using locking characteristic by an external light injection, including: an active region controlling an optical gain and an optical output by current injection; and a passive region having a structure integrated with the active region and moving a cavity mode by current injection or voltage application to lock injection light.

A Mach-Zehnder optical waveguide is disposed in a substrate made of a material having an electro-optic effect. Coplanar-waveguide modulating electrodes are disposed on a principal surface of the substrate. A dielectric layer is disposed on a reverse surface of the substrate. A supporting substrate having a recess is disposed in contact with the dielectric layer such that the recess is located at a position corresponding to a modulating region. The relationship: ∈r>∈s is satisfied where ∈r represents the dielectric constant of the supporting substrate and ∈s represents the dielectric constant of the dielectric constant of solid, liquid, or gaseous substance in the recess.