SURFACE EMITTING QUANTUM CASCADE LASER
First Claim
1. A surface emitting quantum cascade laser comprising:
- an active layer including a plurality of quantum well layers stacked therein and being capable of emitting laser light by intersubband transition; and
a first semiconductor layer provided on the active layer and having a first surface, the first surface including an internal region in which first pits constitute a first two-dimensional grating and an outer peripheral region in which second pits constitute a second two-dimensional grating, grating pitch of the first pits being m times (where m being an integer of 1 or more) grating pitch of the second pits, and the outer peripheral region surrounding the internal region,a first planar shape of an opening end of the first pit being asymmetric with respect to a line passing through barycenter of the first planar shape and being parallel to at least one side of the first two-dimensional grating,a second planar shape of an opening end of the second pit being symmetric with respect to each of lines passing through barycenter of the second planar shape and being parallel to either side of the second two-dimensional grating, andthe laser light having an emission wavelength corresponding to the grating pitch of the second pits and being emitted in a direction generally perpendicular to the active layer from the internal region.
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Accused Products
Abstract
A surface emitting quantum cascade laser includes an active layer and a first semiconductor layer. The active layer includes a plurality of quantum well layers and is capable of emitting laser light by intersubband transition. The first surface includes an internal region and an outer peripheral region. Grating pitch of the first pits is m times grating pitch of the second pits. The outer peripheral region surrounds the internal region. A first planar shape of an opening end of the first pit is asymmetric with respect to a line passing through barycenter of the first planar shape and is parallel to at least one side of the first two-dimensional grating. A second planar shape of an opening end of the second pit is symmetric with respect to each of lines passing through barycenter of the second planar shape and is parallel to either side of the second two-dimensional grating.
5 Citations
17 Claims
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1. A surface emitting quantum cascade laser comprising:
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an active layer including a plurality of quantum well layers stacked therein and being capable of emitting laser light by intersubband transition; and a first semiconductor layer provided on the active layer and having a first surface, the first surface including an internal region in which first pits constitute a first two-dimensional grating and an outer peripheral region in which second pits constitute a second two-dimensional grating, grating pitch of the first pits being m times (where m being an integer of 1 or more) grating pitch of the second pits, and the outer peripheral region surrounding the internal region, a first planar shape of an opening end of the first pit being asymmetric with respect to a line passing through barycenter of the first planar shape and being parallel to at least one side of the first two-dimensional grating, a second planar shape of an opening end of the second pit being symmetric with respect to each of lines passing through barycenter of the second planar shape and being parallel to either side of the second two-dimensional grating, and the laser light having an emission wavelength corresponding to the grating pitch of the second pits and being emitted in a direction generally perpendicular to the active layer from the internal region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification