A plurality of surface emitting lasers are formed on the single surface emitting laser element. The plurality of surface emitting lasers have respective emission wavelengths selected from wavelengths satisfying condition of:
0<λ.sub.1−λ.sub.s≤5.36×10.sup.−5λ.sub.c.sup.2−×5.83×10.sup.−2λ.sub.c+32.4 where a first emission wavelength is λ.sub.1 [nm], a second emission wavelength shorter than the first emission wavelength is λ.sub.s [nm], and a middle wavelength between the first emission wavelength and the second emission wavelength is λ.sub.c [nm]. At least one of the plurality of surface emitting lasers has an emission wavelength different from an emission wavelength of another surface emitting laser.

A light-emitting module includes a substrate, a first surface-emitting laser mounted on the substrate, the first surface-emitting laser having a first engaging portion protruded outward at an end, and a second surface-emitting laser mounted on the substrate, the second surface-emitting laser having a second engaging portion recessed inward at an end. The first surface-emitting laser and the second surface-emitting laser are adjacent to each other. The first engaging portion and the second engaging portion are engaged with each other.

A surface-emitting laser includes a substrate; semiconductor layers provided on the substrate, the semiconductor layers including a lower reflector layer, an active layer, and an upper reflector layer, the semiconductor layers forming a mesa; a first insulating film covering the mesa; and a second insulating film covering the first insulating film, wherein the mesa has a polygonal shape in a direction in which the substrate extends, and a vertex of the mesa in the direction in which the substrate extends has a chamfered portion.

Methods for fabricating vertical cavity surface emitting lasers (VCSELs) on a large wafer are provided. An un-patterned epi layer form is bonded onto a first reflector form. The first reflector form includes a first reflector layer and a wafer of a first substrate type. The un-patterned epi layer form includes a plurality of un-patterned layers on a wafer of a second substrate type. The first and second substrate types have different thermal expansion coefficients. A resulting bonded blank is substantially non-varying in a plane that is normal to an intended emission direction of the VCSEL. A first regrowth is performed to form first regrowth layers, some of which are patterned to form a tunnel junction pattern. A second regrowth is performed to form second regrowth layers. A second reflector form is bonded onto the second regrowth layers, wherein the second reflector form includes a second reflector layer.

A semiconductor laser including: an optical resonator that has a first compound semiconductor layer containing an n-type impurity, a second compound semiconductor layer containing a p-type impurity, and a light-emitting layer provided between the first compound semiconductor layer and the second compound semiconductor layer; and a pulse injection means that injects excitation energy for a sub-nanosecond duration into the optical resonator, wherein the light-emitting layer has an at least five-period multiple quantum well structure, and the semiconductor laser generates optical pulses having a pulse width shorter than 2.5 times the photon lifetime in the optical resonator.

Improved systems and methods for externally modulating a laser. Such systems may comprise a laser section and a modulator section made of an active material that selectively absorbs light from the laser section, where the operating wavelength of the laser is near the exciton absorption peak of the active material of the EAM.

A surface emitting laser according to one embodiment of the present disclosure includes a mesa part including, in order, a first conductivity-type DBR layer, an active layer, a second conductivity-type DBR layer, and a second conductivity-type contact layer. The surface emitting laser further includes: a first conductivity-type contact layer provided in a region on the first conductivity-type DBR layer side in a positional relationship with respect to the mesa part; a first conductivity-type semiconductor layer that is disposed at a position opposed to the mesa part with the first conductivity-type contact layer interposed therebetween, and is in contact with the first conductivity-type contact layer, the first conductivity-type semiconductor layer having a lower impurity concentration than the first conductivity-type contact layer; a first electrode layer in contact with the first conductivity-type contact layer; and a second electrode layer in contact with the second conductivity-type contact layer.

Provided is a semiconductor laser diode including multiple active layers and a grating layer. The semiconductor laser diode includes two (or more than two) active layers, a grating layer, and a tunnel junction. The grating layer and the tunnel junction are provided between the two active layers. The tunnel junction is electrically connected to the two active layers, and the two active layers share and are optically coupled to the grating layer, thereby improving the external quantum efficiency and slope efficiency of the semiconductor laser diode.

A surface emitting laser includes a first reflective layer, an active layer provided on the first reflective layer, and a second reflective layer provided on the active layer. The first reflective layer, the active layer, and the second reflective layer form a mesa, and the mesa has an electrically insulating region and an electrically conductive region. The electrically insulating region is positioned at a center portion of the mesa in a surface direction, and the electrically conductive region includes the first reflective layer, the active layer, and the second reflective layer and is positioned outside the electrically insulating region in such a manner as to surround the electrically insulating region.

A vertical cavity surface-emitting laser configured to emit laser light having a wavelength of 830 nm to 910 nm includes a substrate having a main surface including GaAs, a first distributed Bragg reflector, an active layer, and a second distributed Bragg reflector. The substrate, the first distributed Bragg reflector, the active layer, and the second distributed Bragg reflector are arranged in a first axis direction intersecting the main surface. The main surface has an off angle of 6° or more with respect to a (100) plane. The active layer includes In.sub.xAl.sub.yGa.sub.1-x-yAs (0<x<1, 0≤y<1). The active layer has a strain. An absolute value of the strain is 0.5% to 1.4%.