Abstract: A vertical cavity surface emitting laser (VCSEL) using photonic crystals. Photonic crystals are formed such that the active region of the VCSEL is bounded by the photonic crystals. The photonic crystals have a periodic cavity structure that reflects light of certain wavelengths through the active region of the VCSEL such that laser light at the wavelengths is generated. Additional photonic crystals can be formed to increase the bandwidth of the VCSEL. The photonic crystals can also be combined with distributed bragg reflector layers to form the mirrors of a VCSEL.

Abstract: An optical assembly includes a first lens positioned along a first axis and configured to focus light from a light source along the first axis, and a second lens positioned along the first axis and configured to focus light from the first lens onto an optical target. A third lens is positioned along a second axis and configured to approximately collimate light from a second light source along the second axis, and a reflector positioned along the second axis is configured to reflect light from the third lens onto a fourth lens. The fourth lens is positioned on a third axis angled from the second axis and configured to focus light from the reflector onto an optical detector. Furthermore, the optical assembly is preferably a single molded optic. The optical assembly may be used in an optoelectronic transceiver having an optical subassembly, including a light source and an optical detector. The optical assembly is used to couple a pair of closely spaced optical fibers to the light source and optical detector.

Abstract: The present invention relates generally to optoelectronic devices, and particularly to a submount, pedestal, and bond wire assembly for a transistor outline package. A bottom surface of the submount is connected to a top surface of the pedestal. Each bond wire in a bond wire set is connected to a position on the top surface of the submount, and to a position on the signal line. The signal line is positioned a first distance from the position on the top surface of the submount and a second distance from the pedestal. The submount is sized such that a portion of the bottom and the top surface of the submount extends beyond the top surface of the pedestal such that the first distance is less than the second distance.

Abstract: An optical signal receiver has an increased dynamic range for detecting optical signals whose intensity varies over a wide range. In one embodiment, the optical signal receiver includes a circuit operable to provide a reverse bias voltage and an avalanche photo-diode (APD) coupled to the circuit to receive the reverse bias voltage. The circuit is operable to lower the reverse bias voltage in response to an increase in power of the received optical signals. Since the current gain of the APD is a function of the reverse bias voltage, the circuit indirectly lowers the current gain of the APD in response to the increase in power of the received optical signals. As a result, the optical signal receiver can be used to detect optical signals whose intensity varies over a broad range.

Abstract: A method of maintaining desirable optical performance of optical emitters over temperature variations is disclosed. The optical performance of an optical emitter in terms of power, extinction ratio, jitter, mask margin and general fiber optic transmitter eye quality can be maintained by the present invention over a wide range of temperatures. Advantageously, the present invention enables the use of inexpensive optical emitters in optoelectronic transceivers and optoelectronic transmitters.

Abstract: A means for optically coupling a semiconductor laser to an optical fiber is disclosed. In one embodiment, a volume phase holographic element is disposed on a light-emitting surface of a semiconductor laser. The volume phase holographic element acts as an aberration-corrector for a lens that is disposed between the semiconductor laser and the optical fiber. In this way, an inexpensive lens that is not aberration free can be used. In some embodiments, the volume phase holographic element converts a Gaussian light beam emitted by the semiconductor laser into an annular beam that is more suitable for long distance transmission in multimode fibers.

Abstract: A Semiconductor Optical Amplifier (SOA) with extended bandwidth and the method of fabricating the same are disclosed. In one embodiment, the SOA includes a Multiple Quantum Well (MQW) stacks whose thickness varies along the length of the device. The SOA has a flatter and broader gain spectrum than SOAs with substantially flat MQW stacks.

Abstract: An optoelectronic assembly includes a transistor outline (TO) package that houses an optoelectronic device. The TO package and the optoelectronic device are coupled to a circuit interconnect. The circuit interconnect includes an insulator having a first side for transmitting a signal current between the optoelectronic device and a device external to the TO package, and a second side for transmitting a ground current between the TO package and the external device. For a predefined operating frequency range, the impedance of the circuit interconnect approximately matches the impedance of the signal leads of the TO package and also approximately matches the impedance of the device external to the TO package. The optoelectronic device may include a laser diode or a photo diode. In addition, the present invention is an optoelectronic transceiver including a transmitter optoelectronic assembly and a receiver optoelectronic assembly.

Abstract: An optical assembly includes a first lens positioned along a first axis and configured to focus light from a light source along the first axis, and a second lens positioned along the first axis and configured to focus light from the first lens onto an optical target. A third lens is positioned along a second axis and configured to approximately collimate light from a second light source along the second axis, and a reflector positioned along the second axis is configured to reflect light from the third lens onto a fourth lens. The fourth lens is positioned on a third axis angled from the second axis and configured to focus light from the reflector onto an optical detector. Furthermore, the optical assembly is preferably a single molded optic. The optical assembly may be used in an optoelectronic transceiver having an optical subassembly, including a light source and an optical detector. The optical assembly is used to couple a pair of closely spaced optical fibers to the light source and optical detector.

Abstract: A compact laser package with integrated temperature control is disclosed. In one embodiment, the compact laser package that includes a housing, a window through the housing, a laser emitter disposed in the housing, and an active temperature control device disposed in the housing. The laser emitter is disposed on the active temperature control device and aligned such that optical signals generated by the laser emitter can be emitted through the window without a waveguide. Additionally, the housing has an outline similar to that of a transistor-can. Temperature measuring device and laser power detection device may also be integrated within the laser package.

Abstract: A temperature-controlled optoelectronic module that includes a module housing, a laser mount structure for affixing a laser package in the module housing, an optical fiber receptacle structure disposed adjacent to the laser mount structure, a thermal isolator affixed between the laser mount structure and the optical fiber receptacle structure, and a temperature controller coupled to the laser mount structure and operable to regulate temperature of the laser package is disclosed. In the absence of the thermal isolator, a “thermal short” may be created between the module housing and the laser package, substantially reducing the efficiency of the temperature controller. The presence of the thermal isolator eliminates the “thermal short,” substantially increases the effectiveness of the temperature controller and enables the miniaturization of temperature-controlled optoelectronic transceiver modules.

Abstract: An amplitude-modulated vestigial-sideband, television channel sub-carrier multiplexed optical fiber transmission system includes a laser diode operating linearly throughout the desired range of multiplex frequencies. Such linear laser diode operation is accomplished by limiting leakage current within the laser diode to a very low level. The composite second-order distortion in the optical output signal from the laser diode is down typically 50 db from the video carrier for each channel. For some laser diodes that exhibit slow turn-on in the L-I characteristic, there is a point of inflection in the L-I curve. Operation with the laser biased at or near this point results in extremely linear performance, even though the laser may have insufficient blocking of leakage current to otherwise produce acceptable linearity.

Abstract: A method of achieving radial (x,y) alignment between an active device subassembly and an optical fiber subassembly of an optical package is disclosed. The method relies on the use of mating sections with essentially identical outer diameters. The subassemblies are brought into contact and are first joined at the two points where the edges of the piece parts coincide (flush points). It has been determined that by continuing the attachment process at symmetric locations about one of the flush points, minimal disturbance of throughput efficiency will be maintained. The optical throughput is continually monitored to determined at which particular flush point the attachment process should proceed. In particular, as soon as the throughput efficiency drops below a predetermined value, the attachment process is rotated to continue at the opposite flush point.

Abstract: An optical distribution architecture is disclosed wherein wavelength stabilized continuous wavelength lasers are centrally positioned in tandem with star couplers to distributed laser power among a plurality of lightguide paths. The laser power apportioned to each such path may then be locally or remotely modulated thereby reducing the number of lasers required to equip a network. Advantageously, lightguide fibres are single mode and polarization maintaining.

Abstract: An optical package includes a two-piece fiber subassembly which allows for separate axial and radial alignment of the fiber to the active optical device. The subassembly consists of an inner ferrule encasing the fiber and an outer sleeve which holds the ferrule. The ferrule is moved axially within the sleeve to perfect the axial alignment of the fiber and the device. The sleeve includes a number of openings around its circumference to expose the ferrule. Once axial alignment is achieved, the outer sleeve is attached to the ferrule through these openings to fix the axial alignment.