Abstract: A laser cavity structure is disclosed which pertains to laser resonator geometries possessing circular symmetry, such as in the case of disk or spherical lasers. The disclosed invention utilizes a very-high finesse Bragg reflector (VHF-BR) thin film reflectors of many layer pairs of very small refractive index difference, the VHF-BR deposited on a surface of revolution, thereby forming an optical cavity. These dielectric reflectors are disposed in such a way as to allow selection of preferred low order modes and suppression of parasitic modes while allowing a high cavity Q factor for preferred modes. The invention disclosed, in its preferred embodiments, is seen as particularly useful in applications requiring high efficiency in the production and coupling of coherent radiation. This is accomplished in a cavity design that is relatively compact and economical.

Abstract: A laser is disclosed including a gain section having a distributed feedback grating imposed thereon. An absorption section is embedded in the gain section such that the first and second portions of the distributed feedback grating extend on either side of the electro-absorption section. A controller imposes a substantially DC bias signal on the first and second gain electrodes and imposes a modulation signal encoding digital data on the modulation electrode to generate a frequency modulated signal. In some embodiments, the first and second portions are biased above the lasing threshold and the absorption section is modulated below the lasing threshold to modulate loss in the absorption section.

Abstract: A laser drive circuit and use of digital-to-analog converters is provided, each with a current input and a current output to set current values of partial currents switchable by means of digital channel signals to provide a laser current pulse at least on the basis of a sum of partial currents, wherein at least one current output of one of the digital-to-analog converters is connected to at least one current input of an additional digital-to-analog converter via an analog switch.

Abstract: In an active layer 15 of a semiconductor laser device 3, a refractive index type main waveguide 4 is formed by a ridge portion 9a of a p-type clad layer 17. Side surfaces 4g and 4h of the main waveguide 4 form a relative angle ?, based on a total reflection critical angle ?c at the side surfaces 4g and 4h, with respect to a light emitting surface 1a and a light reflecting surface 1b. The main waveguide 4 is separated by predetermined distances from the light emitting surface 1a and the light reflecting surface 1b, and optical path portions 8a and 8b, for making a laser light L1 pass through, are disposed between one end of the main waveguide 4 and the light emitting surface 1a and between the other end of the main waveguide 4 and the light reflecting surface 1b. The optical path portions 8a and 8b are gain type waveguides and emit light components L2 and L3, which, among the light passing through the optical path portions 8a and 8b, deviate from a direction of a predetermined axis A, to the exterior.

Abstract: Methods and systems for hybrid gain guiding in laser resonators that combines the features of gain guiding and fiber or other types of lasers into a single system. Hybrid gain guiding in laser resonators is not limited to conventional fiber lasers. Any type of gain guided fiber, index guided or anti-guided, is used as an intracavity element to induce loss on high order modes in an otherwise multimode laser system. The gain guided element contributes little gain to the laser oscillator but allows only the lowest order mode to transmit without loss. When the gain guiding fiber length is selected so the loss for a particular cavity mode is greater than the gain, the cavity mode does not lase. Since the gain guiding fiber induces loss for all laser modes other than the lowest order mode it makes sure that the mode one higher than the lowest order mode does not lase and as a result, no other cavity modes lase.

Abstract: A surface emitting laser having a photonic crystal layer 130 on a substrate 105 with an active layer therebetween, in which the photonic crystal layer includes at least a first periodic structure for resonating in an in-plane direction and a second periodic structure for modulating a light intensity distribution in an in-plane direction. The light intensity in the photonic crystal layer is periodically distributed to a region having high light intensity and a region having low light intensity by the second periodic structure. Further, a conductive film 170 for performing current injection into the active layer is selectively provided just above the region having low light intensity. The surface emitting laser provides suppression of light absorption and highly efficient current injection into an active layer to attain a high power.

Abstract: A semiconductor laser device 1 includes infrared and red laser elements 3, 4 provided on a substrate 2, where the infrared element 3 includes a laminate of a first lower clad layer 11, a first active layer 12 and a first upper clad layer 13, and the red element 4 includes a laminate of a second lower clad layer 21, a second active layer 22 and a second upper clad layer 23. The clad layer 11 includes a third lower clad layer 17 formed on the substrate 2, an etching stop layer 18 formed on the third lower clad layer 17, and a fourth lower clad layer 19 formed on the etching stop layer 18 at a region provided with the infrared element 3. The second lower clad layer 21 is formed on the etching stop layer 18 except at the region of the infrared element 3.

Abstract: Disclosed herein are systems and methods for extending one or both of the discharge electrodes in a transverse discharge gas laser chamber in which one or both the electrodes are subject to a dimensional change due to erosion. Electrode extension can be performed to increase the chamber life, increase laser performance over the life of the chamber, or both. Operationally, the inter-electrode spacing may be adjusted to maintain a specific target gap distance between the electrodes or to optimize a specific parameter of the laser output beam such as bandwidth, pulse-to-pulse energy stability, beam size, etc.

Abstract: A vertical external cavity surface emitting laser (VECSEL) using end pumping in which a pumping beam is recycled using a pumping beam reflection layer to increase pumping beam absorption is provided. The VECSEL includes: an active layer for generating and emitting signal light; an external mirror that is separated from and faces a top surface of the active layer and transmits a first portion of the signal light and reflects a second portion of the signal light to the active layer; a first reflection layer contacting a lower surface of the active layer and reflecting the signal light to the external mirror; a pump laser for emitting the pumping beam toward the lower surface of the active layer to excite the active layer; and a second reflection layer contacting the top surface of the active layer and reflecting a portion of the pumping beam back to the active layer.

Abstract: A nitride semiconductor light-emitting device is provided including: a substrate made of a nitride semiconductor; a semiconductor layer made of a nitride semiconductor containing a p-type impurity, the semiconductor layer being formed as contacting an upper surface of the substrate; a first cladding layer made of a nitride semiconductor containing an impurity of a first conductivity type, the first cladding layer being formed on the semiconductor layer; an active layer formed on the first cladding layer; and a second cladding layer made of a nitride semiconductor containing an impurity of a second conductivity type, the second cladding layer being formed on the active layer.

Abstract: A semiconductor laser includes an optical waveguide formed on a semiconductor substrate and capable of generating gain by current injection, and a diffraction grating having a phase shift and provided along the optical waveguide over the overall length of the optical waveguide on the semiconductor substrate. The semiconductor laser is configured such that a Bragg wavelength in a region in the proximity of each of the opposite ends of the optical waveguide is longer than a Bragg wavelength in a region in the proximity of the phase shift in a state in which current injection is not performed for the optical waveguide.

Abstract: Provides is a semiconductor light-emitting device. The semiconductor light-emitting device includes a first conduction-type cladding layer, an active layer, and a second conduction-type cladding layer, on a substrate. Portions of the substrate and the first conduction-type cladding layer are removed. According to the light-emitting device having the above-construction, damage to a grown epitaxial layer is reduced, and a size of an active layer increases, so that a light-emission efficiency increases. Even when a size of a light-emitting device is small, a short-circuit occurring between electrodes can be prevented. Further, brightness and reliability of the light-emitting device are improved.

Abstract: There is provided a light chip and an optical module with high reliability. The light chip 100 according to the present invention is a light chip having a semiconductor laser formed on a first substrate and includes a cavity 18 having an emission surface 22 on the upper surface, a first electrode 24 and a second electrode 26 for driving the semiconductor laser, and a plurality of pad portions 24a, 26a, for flip-chip bonding to a second substrate, respectively connected to the first electrode and the second electrode, wherein the cavity is, seen in a plan view, formed outside a region 25 formed by connecting the outermost peripheries of the plurality of pad portions by straight lines.

Abstract: The invention relates to a high-power fiberoptic laser device comprising at least one laser diode (1) capable of transmitting a pump wave, a triggered optical resonator (22) consisting of a first double-sheathed optical fiber (6), an optical amplifier consisting of a second double-sheathed optical fiber (10), first (33) and second (35) optical coupling means capable of coupling said pump wave onto at least one of the two optical fibers (6) and (10). According to the invention, at least one of the two fibers has a configuration according to which the pump wave coupled to this optical fiber (6) or (10) is partially absorbed, generating a residual pump wave which is coupled to the other optical fiber (6) or (10) by second optical coupling means, and said second optical fiber (10) has a length greater than that of the first optical fiber (6).

Abstract: Circuits and methods for damping out parasitic resonance within a packaged integrated circuit (IC) are provided. A conductive path including a resistor and a conductor is added in parallel with a conductive path that provides power to components within a die of the packaged IC. When implemented in a packaged laser driver integrated circuit (IC), a conductive path including a resistor and a conductor in placed in parallel with a conductive path that provides a laser driver output, of the packaged laser driver IC, to a laser diode. This abstract is not intended to be a complete description of the various embodiments of the present invention.

Abstract: The heterostructures are used for creation of semiconductor injection emission sources: injection lasers, semiconductor amplifying elements, semiconductor optical amplifiers that are used in fiber optic communication and data transmission systems, in optical superhigh-speed computing and switching systems, in development of medical equipment, laser industrial equipment, frequency-doubled lasers, and for pumping solid-state and fiber lasers and amplifiers.

Abstract: A powerful fiber laser system is configured with at least one gain block. The gain block includes an input fiber guiding a pump light, a multiclad active fiber receiving the pump light so that a major portion is absorbed in the core of the active fiber while a minor portion of the pump light propagates in the inner cladding of the active fiber, and a multiclad output fiber. The multiclad output fiber is configured with a core, guiding a signal lased by the core of the active fiber upon absorption of the major portion of the pump light, an inner cladding receiving the minor portion of the pump light and an outer cladding. The inner and outer claddings of the multiclad output fiber have respective refractive indexes which are selected so that the refractive index of the outer cladding is higher than that one of the inner cladding.

Abstract: A semiconductor laser comprises: a ridge structure including a p-type cladding layer, an active layer, and an n-type cladding layer stacked on one another; and a burying layer burying sides of the ridge structure. The burying layer includes a p-type semiconductor layer and an n-type semiconductor layer that form a pn junction; and one of the p-type semiconductor layer and the n-type semiconductor layer has a carrier concentration of 5×1017 cm?3 or less near the pn junction.

Abstract: The present invention provides a laser diode having both a small vertical far-field beam divergence and a large vertical optical confinement factor, as well as a method of fabricating the laser diode. The laser diode comprises a layer stack of semiconductor material, which includes a mode-splitting layer having a low refractive index inserted between waveguide layers. In addition to increasing the vertical near-field beam width of the laser diode, the mode-splitting layer also produces a shoulder in an optical mode generated in an active layer of the layer stack, increasing vertical overlap of the optical mode with the active layer.

Abstract: An optical transmitter with a plurality of transmitter units each providing a Peltier device is disclosed. The Peltier devices of the invention are connected in series with respect to the driver, accordingly, even when the Peltier devices show a relative low impedance, a total load impedance viewed from the driver becomes a substantial value and the total power consumption of the transmitter may be reduced.