Patent classifications
H01S5/028
HIGH SPEED NARROW SPECTRUM MINIARRAY OF VCSELS AND DATA TRANSMISSION DEVICE BASED THEREUPON
An on-chip miniarray of optically-coupled oxide-confined apertures of vertical cavity surface emitting lasers (VCSELs) is realized by etching holes from the chip surface down to at least one aperture layer. Oxidation of the aperture layer results in electrically-isolated apertures suitable for current injection. The lateral distance between the aperture centers and the shape of the aperture is chosen to result in effective interaction of the neighboring optical modes in the related aperture regions through optical field coupling effect causing the interaction-induced splitting of the wavelengths of the optical modes. At least one aperture has a different surface area due to different spacing of the etched holes. Different aperture sizes result in different wavelengths of the coupled modes. Splitting of the cavity modes in a frequency domain 3-100 GHz extends the modulation bandwidth of the device due to photon-photon interaction effects.
Selective deposition of highly reflective coating and/or anti-reflecting coating over apertures of different VCSELs foiining a miniarray allows stabilizing lasing in a single coherent mode of the array. Most preferably, highly reflective coating covers the largest aperture and stabilizes the fundamental mode of the coherent array. Anti-reflecting coatings can be deposited on at least one other aperture to reduce the photon lifetime and increase the homogeneous broadening of the related resonant wavelength. Consequently broadening of the photon-photon interaction resonances between the cavity modes can be controlled. Such resonance broadening allows control over the shape of the current modulation curve of the miniarray of VCSELs with the frequency maximum defined by the splitting of the cavity modes and the broadening defined by the broadening of the photon resonances. An increase in −3dB modulation bandwidth of the VCSEL miniarray up to at least 70 GHz is possible.
Such miniarray of VCSELs enables efficient coupling of the emitted light to a multimode optical fiber with the efficiency of at least 70%.
HIGH SPEED NARROW SPECTRUM MINIARRAY OF VCSELS AND DATA TRANSMISSION DEVICE BASED THEREUPON
An on-chip miniarray of optically-coupled oxide-confined apertures of vertical cavity surface emitting lasers (VCSELs) is realized by etching holes from the chip surface down to at least one aperture layer. Oxidation of the aperture layer results in electrically-isolated apertures suitable for current injection. The lateral distance between the aperture centers and the shape of the aperture is chosen to result in effective interaction of the neighboring optical modes in the related aperture regions through optical field coupling effect causing the interaction-induced splitting of the wavelengths of the optical modes. At least one aperture has a different surface area due to different spacing of the etched holes. Different aperture sizes result in different wavelengths of the coupled modes. Splitting of the cavity modes in a frequency domain 3-100 GHz extends the modulation bandwidth of the device due to photon-photon interaction effects.
Selective deposition of highly reflective coating and/or anti-reflecting coating over apertures of different VCSELs foiining a miniarray allows stabilizing lasing in a single coherent mode of the array. Most preferably, highly reflective coating covers the largest aperture and stabilizes the fundamental mode of the coherent array. Anti-reflecting coatings can be deposited on at least one other aperture to reduce the photon lifetime and increase the homogeneous broadening of the related resonant wavelength. Consequently broadening of the photon-photon interaction resonances between the cavity modes can be controlled. Such resonance broadening allows control over the shape of the current modulation curve of the miniarray of VCSELs with the frequency maximum defined by the splitting of the cavity modes and the broadening defined by the broadening of the photon resonances. An increase in −3dB modulation bandwidth of the VCSEL miniarray up to at least 70 GHz is possible.
Such miniarray of VCSELs enables efficient coupling of the emitted light to a multimode optical fiber with the efficiency of at least 70%.
Semiconductor laser
A semiconductor laser is provided that includes a semiconductor layer sequence and electrical contact surfaces. The semiconductor layer sequence includes a waveguide with an active zone. Furthermore, the semiconductor layer sequence includes a first and a second cladding layer, between which the waveguide is located. At least one oblique facet is formed on the semiconductor layer sequence, which has an angle of 45° to a resonator axis with a tolerance of at most 10°. This facet forms a reflection surface towards the first cladding layer for laser radiation generated during operation. A maximum thickness of the first cladding layer is between 0.5 M/n and 10 M/n at least in a radiation passage region, wherein n is the average refractive index of the first cladding layer and M is the vacuum wavelength of maximum intensity of the laser radiation.
Semiconductor laser
A semiconductor laser is provided that includes a semiconductor layer sequence and electrical contact surfaces. The semiconductor layer sequence includes a waveguide with an active zone. Furthermore, the semiconductor layer sequence includes a first and a second cladding layer, between which the waveguide is located. At least one oblique facet is formed on the semiconductor layer sequence, which has an angle of 45° to a resonator axis with a tolerance of at most 10°. This facet forms a reflection surface towards the first cladding layer for laser radiation generated during operation. A maximum thickness of the first cladding layer is between 0.5 M/n and 10 M/n at least in a radiation passage region, wherein n is the average refractive index of the first cladding layer and M is the vacuum wavelength of maximum intensity of the laser radiation.
QUANTUM DOT SLAB-COUPLED OPTICAL WAVEGUIDE EMITTERS
An optical apparatus comprises a semiconductor substrate and a slab-coupled optical waveguide (SCOW) emitter disposed on the semiconductor substrate. The SCOW emitter comprises an optical waveguide comprising: a first region doped with a first conductivity type; a second region doped with a different, second conductivity type; and an optically active region disposed between the first region and the second region. The optically active region comprises a plurality of quantum dots.
QUANTUM DOT SLAB-COUPLED OPTICAL WAVEGUIDE EMITTERS
An optical apparatus comprises a semiconductor substrate and a slab-coupled optical waveguide (SCOW) emitter disposed on the semiconductor substrate. The SCOW emitter comprises an optical waveguide comprising: a first region doped with a first conductivity type; a second region doped with a different, second conductivity type; and an optically active region disposed between the first region and the second region. The optically active region comprises a plurality of quantum dots.
Highly stable semiconductor lasers and sensors for III-V and silicon photonic integrated circuits
Building blocks are provided for on-chip chemical sensors and other highly-compact photonic integrated circuits combining interband or quantum cascade lasers and detectors with passive waveguides and other components integrated on a III-V or silicon. A MWIR or LWIR laser source is evanescently coupled into a passive extended or resonant-cavity waveguide that provides evanescent coupling to a sample gas (or liquid) for spectroscopic chemical sensing. In the case of an ICL, the uppermost layer of this passive waveguide has a relatively high index of refraction that enables it to form the core of the waveguide, while the ambient air, consisting of the sample gas, functions as the top cladding layer. A fraction of the propagating light beam is absorbed by the sample gas if it contains a chemical species having a fingerprint absorption feature within the spectral linewidth of the laser emission.
Wafer level optic and zoned wafer
A plurality of light sources such as vertical-cavity surface-emitting lasers (VCSELs) are configured to emit non-visible light through emission apertures. Optics are formed over the emission apertures of the plurality of light sources. The optics may provide different tilt angles or divergence angles to the non-visible light emitted by the light sources in the plurality of light sources.
Wafer level optic and zoned wafer
A plurality of light sources such as vertical-cavity surface-emitting lasers (VCSELs) are configured to emit non-visible light through emission apertures. Optics are formed over the emission apertures of the plurality of light sources. The optics may provide different tilt angles or divergence angles to the non-visible light emitted by the light sources in the plurality of light sources.
Thin-film filter for tunable laser
A thin-film device for a wavelength-tunable semiconductor laser. The device includes a cavity between a high-reflectivity facet and an anti-reflection facet designed to emit a laser light of a wavelength in a tunable range determined by two Vernier-ring resonators with a joint-free-spectral-range between a first wavelength and a second wavelength. The device further includes a film including multiple pairs of a first layer and a second layer sequentially stacking to an outer side of the high-reflectivity facet. Each layer in each pair has one unit of respective optical thickness except one first or second layer in one pair having a larger optical thickness. The film is configured to produce inner reflectivity of the laser light from the high-reflectivity facet at least >90% for wavelengths in the tunable range starting from the first wavelength but at least <50% for wavelengths in a 25 nm range around the second wavelength.