A semiconductor optical device may include a semiconductor substrate; a mesa stripe structure that extends in a stripe shape in a first direction on the semiconductor substrate and includes a contact layer on a top layer; an adjacent layer on the semiconductor substrate and adjacent to the mesa stripe structure in a second direction orthogonal to the first direction; a passivation film that covers at least a part of the adjacent layer; a resin layer on the passivation film; an electrode that is electrically connected to the contact layer and extends continuously from the contact layer to the resin layer; and an inorganic insulating film that extends continuously from the resin layer to the passivation film under the electrode, is spaced apart from the mesa stripe structure, and is completely interposed between the electrode and the resin layer.

An optical modulator includes a light-emitting device and an upper electrode disposed on the light-emitting device. The upper electrode includes at least one first electrode portion for injecting a direct current to form a direct-current modulated segment, and a second electrode portion for injecting an alternating current to form an alternating-current modulated segment. The at least one first electrode portion and the second electrode portion are spaced apart from each other, and have a first length and a second length, respectively. The first length is greater than the second length. A method for manufacturing the optical modulator is also provided herein.

A method for forming a Bragg reflector includes after forming first trenches in the stack, which are intended to form structures of the distributed Bragg reflector, forming a sacrificial interlayer at least in the first trenches, depositing a second masking layer at least inside the first trenches, forming second trenches intended to form sidewalls of the laser, removing the second masking layer from inside the first trenches, removing said sacrificial interlayer so as to remove, by lift-off, residues of the second masking layer that remain inside the first trenches, and filling said first trenches with at least one metal material.

A manufacturing method of a nitride-based semiconductor light-emitting element includes: forming an n-type nitride-based semiconductor layer; forming, on the n-type nitride-based semiconductor layer, a light emission layer including a nitride-based semiconductor; forming, on the light emission layer in an atmosphere containing a hydrogen gas, a p-type nitride-based semiconductor layer while doping the p-type nitride-based semiconductor layer with a p-type dopant at a concentration of at least 2.0×10.sup.18 atom/cm.sup.3; and annealing the p-type nitride-based semiconductor layer at a temperature of at least 800 degrees Celsius in an atmosphere not containing hydrogen. In this manufacturing method, a hydrogen concentration of the p-type nitride-based semiconductor layer after the annealing is at most 5.0×10.sup.18 atom/cm.sup.3 and at most 5% of the concentration of the p-type dopant, and a hydrogen concentration of the light emission layer is at most 2.0×10.sup.17 atom/cm.sup.3.

A nitride light emitter includes: a nitride semiconductor light-emitting element including an Al.sub.xGa.sub.1-xN substrate (0≤x≤1) and a multilayer structure above the Al.sub.xGa.sub.1-xN substrate; and a submount substrate on which the nitride semiconductor light-emitting element is mounted. The multilayer structure includes a first clad layer of a first conductivity type, a first light guide layer, a quantum-well active layer, a second light guide layer, and a second clad layer of a second conductivity type which are stacked sequentially from the Al.sub.xGa.sub.1-xN substrate. The multilayer structure and submount substrate are opposed to each other. The submount substrate comprises diamond. The nitride semiconductor light-emitting element has a concave warp on a surface closer to the Al.sub.xGa.sub.1-xN substrate.

A laser structure may include a substrate, an active region arranged on the substrate, and a waveguide arranged on the active region. The waveguide may include a first surface and a second surface that join to form a first angle relative to the active region. A material may be deposited on the first surface and the second surface of the waveguide.

In a method for manufacturing a nitride semiconductor light-emitting element by splitting a semiconductor layer stacked substrate including a semiconductor layer stacked body with a plurality of waveguides extending along the Y-axis to fabricate a bar-shaped substrate, and splitting the bar-shaped substrate along a lengthwise split line to fabricate an individual element, the waveguide in the individual element has different widths at one end portion and the other end portion and the center line of the waveguide is located off the center of the individual element along the X-axis, and in the semiconductor layer stacked substrate including a first element forming region and a second element forming region which are adjacent to each other along the X-axis, two lengthwise split lines sandwiching the first element forming region and two lengthwise split lines sandwiching the second element forming region are misaligned along the X-axis.

A semiconductor optical device includes an element structure layer that includes a mesa stripe extending in a first direction; an electrode film that covers at least an upper surface of the mesa stripe; an electrode pad portion that covers a part of a first region positioned in a second direction, intersecting the first direction, relative to the mesa stripe on an upper surface of the element structure layer and is electrically connected to the electrode film; a first dummy electrode that covers another part of the first region and is electrically insulated from the electrode film; and a second dummy electrode that covers at least a part of a second region positioned in a third direction, opposite to the second direction, relative to the mesa stripe on the upper surface of the element structure layer and is electrically insulated from the electrode film, wherein the first dummy electrode includes a first portion disposed in the first direction relative to the electrode pad portion and a second portion disposed in a fourth direction, opposite to the first direction, relative to the electrode pad portion.

A semiconductor laser element includes: a first conductivity-type cladding layer; a first guide layer disposed above the first conductivity-type cladding layer; an active layer disposed above the first guide layer; and a second conductivity-type cladding layer disposed above the active layer. A window region is formed in a region of the active layer including part of at least one of the front-side end face or the rear-side end face, the first conductivity-type cladding layer consists of (Al.sub.xGa.sub.1-x).sub.0.5In.sub.0.5P, the first guide layer consists of (Al.sub.yGa.sub.1-y).sub.0.5In.sub.0.5P, and the second conductivity-type cladding layer consists of (Al.sub.zGa.sub.1-z).sub.0.5In.sub.0.5P, where x, y, and z each denote an Al composition ratio, 0<x−y<z−y is satisfied, and D/L>0.03 is satisfied, where L denotes a length of the resonator and D denotes a length of the window region in the first direction.

A nitride-based semiconductor light-emitting element includes a semiconductor stack body that includes: an N-type first cladding layer; an N-side guide layer; an active layer that includes a well layer and a barrier layer; a P-side guide layer; and a P-type cladding layer. Band gap energy of the P-side guide layer monotonically increases with an increase in distance from the active layer. An average of the band gap energy of the P-side guide layer is greater than or equal to an average of band gap energy of the N-side guide layer. Band gap energy of the barrier layer is less than or equal to a smallest value of the band gap energy of the N-side guide layer and a smallest value of the band gap energy of the P-side guide layer. A thickness of the P-side guide layer is greater than a thickness of the N-side guide layer.