A distributed Bragg reflector (DBR) structure on a substrate includes a high refractive index layer comprising titanium oxide (TiO2) and a low refractive index layer having a high carbon region and at least one low carbon region that contacts the high refractive index layer. Multiple layers of the high refractive index layer and the low refractive index layer are stacked. Typically, the multiple layers of the high refractive index layer and the low refractive index layer are stacked to a thickness of less than 10 microns. Each of the respective layers of the high refractive index layer and the low refractive index layer have a thickness of less than 0.2 microns.

A distributed Bragg reflector (DBR) structure on a substrate includes a high refractive index layer comprising titanium oxide (TiO2) and a low refractive index layer having a high carbon region and at least one low carbon region that contacts the high refractive index layer. Multiple layers of the high refractive index layer and the low refractive index layer are stacked. Typically, the multiple layers of the high refractive index layer and the low refractive index layer are stacked to a thickness of less than 10 microns. Each of the respective layers of the high refractive index layer and the low refractive index layer have a thickness of less than 0.2 microns.

The embodiment relates to a light-emitting device in which a positional relationship between a modified refractive index region's gravity-center position and the associated lattice point differs from a conventional device, and a production method. In this device, a stacked body including a light-emitting portion and a phase modulation layer optically coupled to the light-emitting portion is on a substrate. The phase modulation layer includes a base layer and plural modified refractive index regions in the base layer. Each modified refractive index region's gravity-center position locates on a virtual straight line passing through a corresponding reference lattice point among lattice points of a virtual square lattice on the base layer's design plane. A distance between the reference lattice point and the modified refractive index region's gravity center along the virtual straight line is individually set such that this device outputs light forming an optical image.

The present embodiment relates to a light-emitting device or the like having a structure capable of reducing one power of 1st-order light with respect to the other power. The light-emitting device includes a substrate, a light-emitting portion, and a phase modulation layer including a base layer and a plurality of modified refractive index regions. Each of the plurality of modified refractive index regions has a three-dimensional shape defined by a first surface facing the substrate, a second surface positioned on a side opposite to the substrate with respect to the first surface, and a side surface. In the three-dimensional shape, at least one of the first surface, the second surface, and the side surface has a portion inclined with respect to a main surface.

A laser diode includes a substrate, an epitaxial structure, an electrode contacting layer and an optical cladding layer. The epitaxial structure is disposed on the substrate, and is formed with a ridge structure opposite to the substrate. The electrode contacting layer is disposed on a top surface of the ridge structure. The optical cladding layer has a refractive index smaller than that of the electrode contacting layer The optical cladding layer includes a first cladding portion which covers side walls of the ridge structure, and a second cladding portion which is disposed on a portion of the top surface of the ridge structure. A method for manufacturing the abovementioned laser diode is also disclosed.

A semiconductor laser device is provided with a semiconductor layer including an active layer and a plurality of cladding layers sandwiching the active layer. The active layer includes a stripe-shaped active region, a pair of first refractive index regions and a pair of second refractive index regions sandwiching the active layer and the pair of first refractive index regions. When is the laser oscillation wavelength, n.sub.a is the effective refractive index of the active region, n.sub.c is the effective refractive index of the first refractive index regions, n.sub.t is the effective refractive index of the second refractive index regions, w is the width of the active region, and m is a positive integer, the semiconductor laser device satisfies n.sub.a>n.sub.t>n.sub.c, and the conditions of equations (5), (8) and (9).

A split electrode vertical cavity optical device includes an n-type ohmic contact layer, first through fifth ion implant regions, cathode and anode electrodes, first and second injector terminals, and p and n type modulation doped quantum well structures. The cathode electrode and the first and second ion implant regions are formed on the n-type ohmic contact layer. The third ion implant region is formed on the first ion implant region and contacts the p-type modulation doped QW structure. The fourth ion implant region encompasses the n-type modulation doped QW structure. The first and second injector terminals are formed on the third and fourth ion implant regions, respectively. The fifth ion implant region is formed above the n-type modulation doped QW structure and the anode electrode is formed above the fifth ion implant region.

An in-plane-emitting semiconductor diode laser employs a surface-trapped optical mode existing at a boundary between a distributed Bragg reflector and a homogeneous medium, dielectric or air. The device can operate in both TM-polarized and TE-polarized modes. The mode exhibits an oscillatory decay in the DBR away from the surface and an evanescent decay in the dielectric or in the air. The active region is preferably placed in the top part of the DBR close to the surface. The mode behavior strongly depends on the wavelength of light, upon increase of the wavelength the mode becomes more and more extended into the homogeneous medium, the optical confinement factor of the mode in the active region drops until the surface-trapped mode vanishes. Upon a decrease of the wavelength, the leakage loss of the mode into the substrate increases. Thus, there is an optimum wavelength, at which the laser threshold current density is minimum, and at which the lasing starts. This optimum wavelength is temperature-stabilized, and shifts upon temperature increase at a low rate less than 0.1 nm/K, indicating wavelength-stabilized operation of the device. The approach applies also to semiconductor optical amplifiers or semiconductor gain chips which are also wavelength-stabilized. Reflectivity of the surface-trapped mode from an uncoated facet of the device can be extremely low, also <1E-4 or even <1E-5 which is particularly advantageous for amplifiers or gain chips. For diode lasers, a specific intermediate reflective coating can be deposited on the facet to put its reflectivity into a range from 0.5% to 3%, which lies within targeted values for lasers. An optical integrated circuit can employ wavelength-stabilized amplifiers operating in a surface-trapped mode, wherein such devices amplify light propagating along a dielectric waveguide.

An in-plane-emitting semiconductor diode laser employs a surface-trapped optical mode existing at a boundary between a distributed Bragg reflector and a homogeneous medium, dielectric or air. The device can operate in both TM-polarized and TE-polarized modes. The mode exhibits an oscillatory decay in the DBR away from the surface and an evanescent decay in the dielectric or in the air. The active region is preferably placed in the top part of the DBR close to the surface. The mode behavior strongly depends on the wavelength of light, upon increase of the wavelength the mode becomes more and more extended into the homogeneous medium, the optical confinement factor of the mode in the active region drops until the surface-trapped mode vanishes. Upon a decrease of the wavelength, the leakage loss of the mode into the substrate increases. Thus, there is an optimum wavelength, at which the laser threshold current density is minimum, and at which the lasing starts. This optimum wavelength is temperature-stabilized, and shifts upon temperature increase at a low rate less than 0.1 nm/K, indicating wavelength-stabilized operation of the device. The approach applies also to semiconductor optical amplifiers or semiconductor gain chips which are also wavelength-stabilized. Reflectivity of the surface-trapped mode from an uncoated facet of the device can be extremely low, also <1E4 or even <1E5 which is particularly advantageous for amplifiers or gain chips. For diode lasers, a specific intermediate reflective coating can be deposited on the facet to put its reflectivity into a range from 0.5% to 3%, which lies within targeted values for lasers. An optical integrated circuit can employ wavelength-stabilized amplifiers operating in a surface-trapped mode, wherein such devices amplify light propagating along a dielectric waveguide.

A light-emitting device includes: a substrate; a laminated structure provided at the substrate and having a plurality of columnar parts; and an electrode provided on a side opposite to a side of the substrate, of the laminated structure. The columnar part has: a first semiconductor layer; a second semiconductor layer having a different electrical conductivity type from the first semiconductor layer; and an active layer provided between the first semiconductor layer and the second semiconductor layer. The laminated structure has: a light propagation layer provided between the active layers of the columnar parts that are next to each other; a first low-refractive-index part provided between the light propagation layer and the substrate and having a lower refractive index than a refractive index of the light propagation layer; and a second low-refractive-index part provided between the light propagation layer and the electrode and having a lower refractive index than the refractive index of the light propagation layer.