Light emitting device, ranging device and movable object
AssigneeCanon Kabushiki Kaisha
InventorsTAKESHI UCHIDA, TAKAKO SUGA
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Abstract
The light emitting device includes a semiconductor light emitting element including a first reflector, a resonator spacer including an active layer, and a second reflector stacked in this order over a semiconductor substrate. The semiconductor light emitting element includes a saturable absorption layer provided between the semiconductor substrate and the second reflector. The semiconductor light emitting element is configured to emit light having a profile that has a maximum peak value and converges to a stable value of a predetermined light intensity after the maximum peak value.
Claims21
A light emitting device comprising:
- a semiconductor light emitting element including a first reflector, a resonator spacer including an active layer, and a second reflector stacked in this order over a semiconductor substrate,
- wherein the semiconductor light emitting element includes a saturable absorption layer provided between the semiconductor substrate and the second reflector, and
- wherein the semiconductor light emitting element is configured to emit light having a profile that has a maximum peak value and converges to a stable value of a predetermined light intensity after the maximum peak value.
A light emitting device comprising:
- a semiconductor light emitting element including a first reflector, a resonator spacer including an active layer, and a second reflector stacked in this order over a semiconductor substrate,
- wherein the semiconductor light emitting element includes a saturable absorption layer provided between the semiconductor substrate and the second reflector, and
- wherein the semiconductor light emitting element satisfies the following relationship:
- Γs×gmax(Iop)>Γa×α2+αm+αi
- where Γs is an optical confinement coefficient of the active layer;
- Γa is an optical confinement coefficient of the saturable absorption layer;
- gmax(Iop) is a maximum gain in the active layer obtained when a current value injected from a driving unit is lop;
- α2 is an absorption coefficient of the saturable absorption layer;
- αm is a mirror loss;
- and αi is a light absorption by carriers.
Alight emitting device comprising:
- a semiconductor light emitting element including a first reflector, a resonator spacer including an active layer, and a second reflector stacked in this order over a semiconductor substrate,
- wherein the active layer includes 6 to 50 quantum well layers,
- wherein the semiconductor light emitting element further includes a saturable absorption layer provided between the semiconductor substrate and the second reflector, and
- wherein an optical thickness of the resonator spacer is not less than a thickness corresponding to 5 times a resonance wavelength.
Alight emitting device comprising:
- a semiconductor light emitting element including a first reflector, a resonator spacer including an active layer, and a second reflector stacked in this order over a semiconductor substrate,
- wherein the semiconductor light emitting element includes a saturable absorption layer provided between the semiconductor substrate and the second reflector, and
- wherein the active layer includes a plurality of quantum well layers and a plurality of barrier layers provided between the plurality of quantum well layers, and
- wherein the barrier layers are formed of GaAs.
Dependencies are inferred from the claim text.