Abstract: According to embodiments of the present invention, an optical transponder includes a transmitter optical subassembly (TOSA). In one embodiment, the electrical ground of the TOSA may be DC-isolated from chassis ground of the transponder using a blocking capacitor that couples the AC signal path to VDD and that allows the case of the TOSA to float. In an alternative embodiment, the electrical ground of the TOSA may be DC-isolated from chassis ground of the transponder using a blocking capacitor that couples the AC signal path to VDD and a resistor that couples the DC bias level path to internal electrical ground or transponder case ground.

Abstract: According to embodiments of the present invention, an optical transponder includes a transmitter optical subassembly (TOSA). In one embodiment, the electrical ground of the TOSA may be DC-isolated from chassis ground of the transponder using a blocking capacitor that couples the AC signal path to VDD and that allows the case of the TOSA to float. In an alternative embodiment, the electrical ground of the TOSA may be DC-isolated from chassis ground of the transponder using a blocking capacitor that couples the AC signal path to VDD and a resistor that couples the DC bias level path to internal electrical ground or transponder case ground.

Abstract: An arrayed waveguide grating may include a transversal filter to compensate for dispersion. The characteristics of each of the waveguides making up the waveguide region of the arrayed waveguide grating can be adjusted to achieve the desired compensation.

Abstract: An optical component formed from a fiber directly coupled to a photodiode without any intervening optical components such as mirrors or lenses is disclosed. The optical component includes a stripped optical fiber having a core with a flat distal end that extends through a ferrule. The distal flat end of the core is printed with an annular coating of metal leaving a central portion of the core uncovered. The coated flat end of the core is initially aligned with an aperture or active area of a rear side of a back-illuminated photodiode which also includes a coating of metal. With the two parts in abutting engagement, a reflow or a partial melting process is carried out to directly couple the fiber core to the photodiode.

Abstract: A transistor, such as a FET or bipolar transistor, may be gate or base coupled to a laser driver output stage to receive a varying voltage from a driver output stage. The transistor converts the varying voltage to a varying current. The transistor, in series with the laser, may be coupled to a supply voltage on one side and ground on the other side. Thus, the current supplied to the laser diode is a function of the drive supplied to the transistor's base or gate.

Abstract: An optical component formed from a fiber directly coupled to a photodiode without any intervening optical components such as mirrors or lenses is disclosed. The optical component includes a stripped optical fiber having a core with a flat distal end that extends through a ferrule. The distal flat end of the core is printed with an annular coating of metal leaving a central portion of the core uncovered. The coated flat end of the core is initially aligned with an aperture or active area of a rear side of a back-illuminated photodiode which also includes a coating of metal. With the two parts in abutting engagement, a reflow or a partial melting process is carried out to directly couple the fiber core to the photodiode.

Abstract: An arrayed waveguide grating may include a transversal filter to compensate for dispersion. The characteristics of each of the waveguides making up the waveguide region of the arrayed waveguide grating can be adjusted to achieve the desired compensation.

Abstract: An arrayed waveguide may be used to separate out the highest and a next highest efficiency diffraction orders. The highest efficiency diffraction order may be used as the main signal and the next highest efficiency diffraction order may be separated by an arrayed waveguide and passed to a detector array. Thus, the next highest efficiency diffraction order for each of the channels of a wavelength division multiplexed signal may be detected for power monitoring purposes.