It is provided a method for fabricating an electroabsorption modulated laser comprising generating a single mode laser section and an electroabsorption modulator section, comprising fabricating at least one n-doped layer of the laser section and at least one n-doped layer of the modulator section; generating an isolating section for electrically isolating at least the n-doped layer of the laser section and the n-doped layer of the modulator section from one another. Generating the isolating section comprises epitaxially growing at least one isolating layer and structuring the isolating layer before the generation of the n-doped layer of the laser section and the n-doped layer of the modulator section.

Techniques to achieve higher power/shorter pulses with a laser diode. By initially applying a static reverse bias across the laser diode, the laser diode can turn on at a larger inductor current. When the laser diode is initially reverse biased, depletion charge and diffusion charge can be populated before the laser diode will lase. This causes the laser diode to initially turn on at a larger inductor current, which will reduce the rise time, thereby achieving higher power/shorter pulses.

An optical signal transmission apparatus including a temperature-independent wavelength tunable laser includes a distributed Bragg reflector (DBR) laser including a DBR mirror region configured to convert a wavelength of an output optical signal based on a first supply current, and an optical gain region configured to control a gain of the output optical signal based on a second supply current, a semiconductor optical amplifier (SOA) configured to amplify an optical signal output from the DBR laser based on a third supply current, and a processor configured to supply a compensation current to the optical gain region based on a wavelength conversion request, to suppress a wavelength overshoot due to a carrier effect caused by the first supply current provided to the DBR mirror region.

A multi-wavelength integrated device (5) including plural semiconductor lasers (6) and plural modulators (7) modulating output beams of the plural semiconductor lasers (6) respectively is mounted on the stem (1). Plural leads (10) penetrates through the stem (1) and are connected to the plural semiconductor lasers (6) and the plural modulators (7) respectively. Each lead (10) is a coaxial line in which plural layers are concentrically overlapped with one another. The coaxial line includes a high frequency signal line (12) transmitting a high frequency signal to the modulator (7), a GND line (14), and a feed line (16) feeding a DC current to the semiconductor laser (6). The high frequency signal line (12) is arranged at a center of the coaxial line. The GND line (14) and the feed line (16) are arranged outside the high frequency signal line (12).

A system and method for tuning and infrared source laser in the Mid-IR wavelength range. The system and method comprising, at least, a plurality of individually tunable emitters, each emitter emitting a beam having a unique wavelength, a grating, a mirror positioned after the grating to receive at least one refracted order of light of at least one beam and to redirect the beam back towards the grating, and a micro-electro-mechanical systems device containing a plurality of adjustable micro-mirrors.

A device for generating a laser pulse. The device includes a laser diode that includes a first diode and a second diode, so that the laser diode includes a first anode, a second anode, and a cathode. The device further includes a first voltage potential that is electrically connected to the second anode, a second voltage potential that has a lower value than the first voltage potential, a first switch that is electrically connected to the first anode and to the second voltage potential, and a second switch that is electrically connected to the cathode and to the second voltage potential. A resistor is electrically connected to the first anode and to the second anode.

A multi-wavelength integrated device (5) including plural semiconductor lasers (6) and plural modulators (7) modulating output beams of the plural semiconductor lasers (6) respectively is mounted on the stem (1). Plural leads (10) penetrates through the stem (1) and are connected to the plural semiconductor lasers (6) and the plural modulators (7) respectively. Each lead (10) is a coaxial line in which plural layers are concentrically overlapped with one another. The coaxial line includes a high frequency signal line (12) transmitting a high frequency signal to the modulator (7), a GNU line (14), and a feed line (16) feeding a DC current to the semiconductor laser (6). The high frequency signal line (12) is arranged at a center of the coaxial line. The GND line (14) and the feed line (16) are arranged outside the high frequency signal line (12).

A directly modulated semiconductor laser whose optical output can be modulated by varying the transmittance of an end reflector of the laser cavity. In an example embodiment, the end reflector can be implemented using a lightwave circuit in which optical waveguides are arranged to form an optical interferometer. At least one of the optical waveguides may include a waveguide section configured to modulate the phase of an optical beam passing therethrough in response to an electrical radio-frequency drive signal in a manner that causes the transmittance and reflectance of the end reflector to be modulated accordingly. Advantageously, relatively high (e.g., >10 GHz) phase and/or amplitude modulation speeds of the optical output can be achieved in this manner to circumvent the inherent modulation-speed limitations of the laser's gain medium.

A system and method for tuning and infrared source laser in the Mid-IR wavelength range. The system and method comprising, at least, a plurality of individually tunable emitters, each emitter emitting a beam having a unique wavelength, a grating, a mirror positioned after the grating to receive at least one refracted order of light of at least one beam and to redirect the beam back towards the grating, and a micro-electro-mechanical systems device containing a plurality of adjustable micro-mirrors.

A semiconductor light emitting element has a laminated structure formed by laminating a first compound semiconductor layer, an active layer, and a second compound semiconductor layer. The semiconductor light emitting element satisfies I.sub.2>I.sub.1, where I.sub.1 is an operating current range when the temperature of the active layer is T.sub.1, and I.sub.2 is the operating current range when the temperature of the active layer is T.sub.2 (where T.sub.2>T.sub.1). The semiconductor light emitting element satisfies P.sub.2>P.sub.1, where P.sub.1 is a maximum optical output emitted when the temperature of the active layer is T.sub.1, and P.sub.2 is the maximum optical output emitted when the temperature of the active layer is T.sub.2 (where T.sub.2>T.sub.1).