摘要:
The present invention provides a low noise multimode VCSEL that can be used to transmit data reliably on multimode optical media at data rates up to and exceeding 1 gigabit per second with bit error rates less than 1.times.10.sup.-9 errors/bit. In contrast to conventional multimode lasers where optimal mirror reflectivity is designed for maximum power output, in the present invention mirror reflectivity is increased to a point where the output power is less than half the maximum output power. Preferably, the reflectivity of the first and second mirror regions of the multimode laser is high, typically greater than 99.5%.
摘要:
A surface-emitting laser (“SEL”) having predictable filamentation initiation. The SEL includes a light generation layer and first and second mirror layers. The first and second mirror layers reflect light generated in the light generation region back toward the light generation region. Each of the mirrors reflects light such that it adds coherently to the light generated in the light generation region or to the light reflected from the other mirror. One of the mirrors includes a localized imperfection which causes light interacting therewith to be attenuated or shifted in phase relative to light that does not interact with the imperfection region. As a result, lasing filaments are preferentially initiated in the regions adjacent to the localized imperfection.
摘要:
An optical communication system using a relatively large-area vertical-cavity surface-emitting laser. The laser has an opening larger than about eight micrometers and is coupled to a multimode optical fiber. The laser is driven into multiple transverse mode operation, which includes multiple filamentation as well as operation in a single cavity.
摘要:
A controllable optical ring resonator, a photonic system and a method of controlling an optical ring resonator employ control electrodes periodically spaced apart along a closed loop optical path of an optical waveguide. The controllable optical ring resonator includes the optical waveguide and a plurality of the periodically spaced control electrodes. The photonic system includes an input optical waveguide segment and the controllable optical ring resonator adjacent and optically coupled to the segment. The method includes providing the plurality of periodically spaced control electrodes, providing an optical signal within the optical path, and addressing one or more of the control electrodes to interact with the optical signal within the optical path.
摘要:
A VCSEL 101 comprising an optical cavity having an optical loss and a loss-determining element 117 coupled to the optical cavity. The loss-determining element 117 progressively increases the optical loss of the optical cavity with increasing lateral distance from the optical axis 105. The optical cavity includes a first mirror region 111, a second mirror region 107, a plane light-generating region 125 sandwiched between the first mirror region 111 and the second mirror region 107, perpendicular to the optical axis 105, and an element 113 that defines the lateral extent of the optical cavity in the plane of the light-generating region 125. The first mirror region 111 and the second mirror region 107 are both conductive and have opposite conductivity modes.
摘要:
A contact structure for a vertical cavity surface emitting laser is described. The contact structure comprises a surface metal contact, a degeneratively doped layer of low bandgap material less than 200 .ANG. thick, and a plurality of current spreading layers. The contact structure provides a low ohmic path between the metal contact and the active region of the vertical cavity surface emitting laser.
摘要:
A controllable optical ring resonator, a photonic system and a method of controlling an optical ring resonator employ control electrodes periodically spaced apart along a closed loop optical path of an optical waveguide. The controllable optical ring resonator includes the optical waveguide and a plurality of the periodically spaced control electrodes. The photonic system includes an input optical waveguide segment and the controllable optical ring resonator adjacent and optically coupled to the segment. The method includes providing the plurality of periodically spaced control electrodes, providing an optical signal within the optical path, and addressing one or more of the control electrodes to interact with the optical signal within the optical path.
摘要:
A nanowire-based photodiode and an interdigital p-i-n photodiode use an i-type semiconductor nanowire in an i-region of the photodiode. The nanowire-based photodiode includes a first sidewall of a first semiconductor doped with a p-type dopant, a second sidewall of the first semiconductor doped with an n-type dopant, and an intrinsic semiconductor nanowire that spans a trench between the first and second sidewalls. The trench is wider at a top than at a bottom adjacent to a substrate. The first semiconductor of one or both of the first sidewall and the second sidewall is single crystalline and together the first sidewall, the nanowire and the second sidewall form a p-i-n semiconductor junction of the photodiode.
摘要:
A negative index material (or metamaterial) crossbar includes a first layer of approximately parallel nanowires and a second layer of approximately parallel nanowires that overlay the nanowires in the first layer. The nanowires in the first layer are approximately perpendicular in orientation to the nanowires in the second layer. Each nanowire of the first layer and each nanowire of the second layer has substantially regularly spaced fingers. The crossbar further includes resonant elements at nanowire intersections between the respective layers. Each resonant element includes two fingers of a nanowire in the first layer and two fingers of a nanowire in the second layer.
摘要:
A nanostructure includes a highly conductive microcrystalline layer, a bipolar nanowire, and another layer (18, 30). The highly conductive microcrystalline layer includes a microcrystalline material and a metal. The bipolar nanowire has one end attached to the highly conductive microcrystalline layer and another end attached to the other layer.