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US 12,719,240 B2Granted
Quantum cascade laser element, quantum cascade laser device, and method for manufacturing quantum cascade laser element
AssigneeHamamatsu Photonics K.K.
InventorAtsushi Sugiyama
Life of this patent
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Abstract
A quantum cascade laser element includes: a semiconductor substrate; a semiconductor laminate including an active layer and having a first end surface and a second end surface facing each other in an optical waveguide direction; a first electrode; a second electrode; and an anti-reflection film formed on the first end surface. The semiconductor laminate is configured to oscillate laser light having a central wavelength of 7.5 μm or more. The anti-reflection film includes at least one of at least one layer of a CeO2 film formed by continuous sputtering and vacuum evaporation and a plurality of layers of CeO2 films formed by discrete sputtering and vacuum evaporation.
Claims13
A quantum cascade laser element comprising:
- a semiconductor substrate;
- a semiconductor laminate formed on the semiconductor substrate, including an active layer having a quantum cascade structure, and having a first end surface and a second end surface facing each other in an optical waveguide direction;
- a first electrode formed on a surface on an opposite side of the semiconductor laminate from the semiconductor substrate;
- a second electrode formed on a surface on an opposite side of the semiconductor substrate from the semiconductor laminate;
- and
- an anti-reflection film formed on the first end surface,
- wherein the semiconductor laminate is configured to oscillate laser light having a central wavelength of 7.5 μm or more, and
- the anti-reflection film includes at least one selected from the group consisting of:
- at least one layer of a CeO2 film formed by continuous sputtering and vacuum evaporation;
- and
- a plurality of layers of CeO2 films formed by discrete sputtering and vacuum evaporation,
- in the at least one layer of the CeO2 film formed by the continuous sputtering and vacuum evaporation, a CeO2 region formed by sputtering and a CeO2 region formed by vacuum evaporation are continuous with each other, and
- in the plurality of layers of the CeO2 films formed by the discrete sputtering and vacuum evaporation, the plurality of layers of the CeO2 films are continuous with each other.
10 more elements
A quantum cascade laser device comprising:
- a quantum cascade laser element comprising:
- a semiconductor substrate;
- a semiconductor laminate formed on the semiconductor substrate, including an active layer having a quantum cascade structure, and having a first end surface and a second end surface facing each other in an optical waveguide direction;
- a first electrode formed on a surface on an opposite side of the semiconductor laminate from the semiconductor substrate;
- a second electrode formed on a surface on an opposite side of the semiconductor substrate from the semiconductor laminate;
- and
- an anti-reflection film formed on the first end surface,
- wherein the semiconductor laminate is configured to oscillate laser light having a central wavelength of 7.5 μm or more, and
- the anti-reflection film includes at least one selected from the group consisting of:
- at least one layer of a CeO2 film formed by continuous sputtering and vacuum evaporation;
- and
- a plurality of layers of CeO2 films formed by discrete sputtering and vacuum evaporation,
- wherein the anti-reflection film includes a body portion formed on the first end surface, and an additional portion formed on a surface on an opposite side of the second electrode from the semiconductor substrate,
- the additional portion includes a second end portion in which the more the second end portion is distant from the first end surface in the optical waveguide direction, the smaller a thickness of the second end portion is, and
- the second end portion has a second side surface intersecting the surface of the second electrode;
- a support portion supporting the quantum cascade laser element;
- and
- a joining member joining an electrode pad of the support portion and the second electrode in a state where the semiconductor substrate is located on the support portion side with respect to the semiconductor laminate,
- wherein a maximum value of a thickness of the joining member is smaller than a maximum value of a thickness of the additional portion between the electrode pad and the second electrode.
16 more elements
A quantum cascade laser device comprising:
- a quantum cascade laser element comprising:
- a semiconductor substrate;
- a semiconductor laminate formed on the semiconductor substrate, including an active layer having a quantum cascade structure, and having a first end surface and a second end surface facing each other in an optical waveguide direction;
- a first electrode formed on a surface on an opposite side of the semiconductor laminate from the semiconductor substrate;
- a second electrode formed on a surface on an opposite side of the semiconductor substrate from the semiconductor laminate;
- and
- an anti-reflection film formed on the first end surface,
- wherein the semiconductor laminate is configured to oscillate laser light having a central wavelength of 7.5 μm or more, and
- the anti-reflection film includes at least one selected from the group consisting of:
- at least one layer of a CeO2 film formed by continuous sputtering and vacuum evaporation;
- and
- a plurality of layers of CeO2 films formed by discrete sputtering and vacuum evaporation,
- wherein the anti-reflection film includes a body portion formed on the first end surface, and an additional portion formed on a surface on an opposite side of the first electrode from the semiconductor laminate,
- the additional portion includes a first end portion in which the more the first end portion is distant from the first end surface in the optical waveguide direction, the smaller a thickness of the first end portion is, and
- the first end portion has a first side surface intersecting the surface of the first electrode;
- a support portion supporting the quantum cascade laser element;
- and
- a joining member joining an electrode pad of the support portion and the first electrode in a state where the semiconductor laminate is located on the support portion side with respect to the semiconductor substrate,
- wherein a maximum value of a thickness of the joining member is smaller than a maximum value of a thickness of the additional portion between the electrode pad and the first electrode.
16 more elements
A method for manufacturing the quantum cascade laser element, the quantum cascade laser element comprising:
- a semiconductor substrate;
- a semiconductor laminate formed on the semiconductor substrate, including an active layer having a quantum cascade structure, and having a first end surface and a second end surface facing each other in an optical waveguide direction;
- a first electrode formed on a surface on an opposite side of the semiconductor laminate from the semiconductor substrate;
- a second electrode formed on a surface on an opposite side of the semiconductor substrate from the semiconductor laminate;
- and
- an anti-reflection film formed on the first end surface,
- wherein the semiconductor laminate is configured to oscillate laser light having a central wavelength of 7.5 μm or more, and
- the anti-reflection film includes at least one selected from the group consisting of:
- at least one layer of a CeO2 film formed by continuous sputtering and vacuum evaporation;
- and
- a plurality of layers of CeO2 films formed by discrete sputtering and vacuum evaporation,
- the method comprising:
- a step of preparing a laser bar including a plurality of portions each corresponding to one set of the semiconductor substrate, the semiconductor laminate, the first electrode, and the second electrode, the plurality of portions one-dimensionally arranged in a direction perpendicular to the optical waveguide direction;
- a step of performing at least one selected from the group consisting of:
- formation of at least one layer of CeO2 film by continuous sputtering and vacuum evaporation, and
- formation of a plurality of layers of CeO2 films by discrete sputtering and vacuum evaporation,
- on an end surface corresponding to the first end surface in each of the plurality of portions of the laser bar, and thereby forming an anti-reflection layer including a plurality of portions each corresponding to the anti-reflection film, on the laser bar;
- and
- a step of dividing the laser bar and the anti-reflection layer for each of the plurality of portions.
16 more elements
Dependencies are inferred from the claim text.