The first capacitor is opposed to and electrically connected to the first back electrode. The second capacitor is opposed to and electrically connected to the second back electrode. Each of the first circuit and the second circuit has a main region that overlaps with a corresponding one of the first capacitor and the second capacitor. At least one circuit of the first circuit and the second circuit has an extension region extending from the main region toward another circuit of the first circuit and the second circuit. At least one of one of the pair of first wires and the second wire is bonded to the extension region.

A predriver includes a first transistor for receiving a signal at a gate thereof, a load resistance, a first peaking inductor, a second peaking inductor, a second transistor for receiving a control voltage at a gate thereof, a third transistor for receiving a control voltage at a gate thereof, an inductor for suppressing the group delay, a first peaking capacitor, a second peaking capacitor, and a peaking resistance.

Provided are a printed circuit board configured to achieve reduction in impedance of a differential transmission line extending in a stacking direction, and an optical module. The printed circuit board includes a stacking-direction differential transmission line extending in the stacking direction, including: a differential signal via pair including a first signal via and a second signal via; and a plurality of conductor plate pairs each including a first conductor plate expanding outward from the first signal via, and a second conductor plate expanding outward from the second signal via. With respect to a perpendicular bisector of a center-of-gravity line segment connecting centers of gravity of the first and second signal vias, in each of the plurality of conductor plate pairs, centers of gravity of contours of the first and second conductor plates are located on inner sides of the centers of gravity.

The DML driver includes: a post driver which supplies a driving current to the LD; and a pre-driver which drives the post driver in response to a modulated signal. The pre-driver has a transistor, a peaking inductor, a peaking inductor, a group delay inhibition inductor, and a peaking capacitor.

The Hybrid Photonic Plasmonic Interconnect (HyPPI) combines both low loss photonic signal propagation and passive routing with ultra-compact plasmonic devices. These optical interconnects therefore uniquely combine fast operational data-bandwidths (in hundreds of Gbps) for light manipulation with low optical attenuation losses by hybridizing low loss photonics with strong light-matter-interaction plasmonics to create, modulate, switch and detect light efficiently at the same time. Initial implementations were considered for on-chip photonic integration, but also promising for free space or fiber-based systems. In general two technical options exist, which distinguished by the method the electric-optic conversion is executed: the extrinsic modulation method consists of an continuous wave source such as an LED or laser operating at steady power output, and signal encoding is done via an electro-optic modulator downstream of the source in the interconnect. In contrast, in the intrinsic method, the optical source is directly amplitude modulated.

A power control system comprising a laser driver that receives a data signal, and responsive to a modulation control signal and a bias control signal, processes the data signal to drive a laser to generate an optic signal that represents the data signal. A monitor photodiode configured to receive the optic signal and generate a monitor photodiode signal.

A modulation control path, that processes a monitor photodiode signal and a reference signal, including at least one filter and at least one mixer. The modulation control path generates a modulation control signal. A bias control path, that processes the monitor photodiode signal and the reference signal, that includes at least one filter and at least one average weighting module to generate a modulation control signal. The bias control path and the modulation control path processing reduces the effect of the error in the monitor photodiode signal.

A power control method for a laser system comprising laser diodes arranged in diode banks is provided. Each diode bank comprises at least one of the laser diodes and has a maximum power. The method comprises operating a first diode bank of the diode banks to output a first power; and concurrently operating other of the diode banks to output other powers, at least one of the other powers being different than the first power.

A solid-state light source with built-in access resistance modulation is described. The light source can include an active region configured to emit electromagnetic radiation during operation of the light source. The active region can be formed at a p-n junction of a p-type side with a p-type contact and a n-type side with a n-type contact. The light source includes a control electrode configured to modulate an access resistance of an access region located on the p-type side and/or an access resistance of an access region located on the n-type side of the active region. The solid-state light source can be implemented in a circuit, which includes a voltage source that supplies a modulation voltage to the control electrode to modulate the access resistance(s).

Before writing to a heat-assisted magnetic recording medium, a current of a laser is modulated about a default threshold current level. A modulation level of an optical power sensor is measured, the optical power sensor being coupled to detect optical output of the laser in response to the modulated current. A bias current for subsequent activation of the laser is adjusted based on the modulation level of the optical power sensor.

A burst optical signal transmission device which includes a light source for generating and outputting burst signal light, a light source driving circuit for outputting, to the light source, a driving signal for switching between an output time and a stop time of the burst signal light, based on a burst control signal, and a pre-emphasis circuit for outputting a pre-emphasis control signal for superimposing an additional signal for charging a capacitor included in the light source, onto the driving signal, at a timing in the vicinity of the beginning of the burst control signal.