In order to further develop a circuit arrangement (CR; CR′) for receiving optical signals (SI) from at least one optical guide (GU), said circuit arrangement (CR; CR′) comprising: at least one light-receiving component (PD) for converting the optical signals (SI) into electrical current signals (I.sub.PD), at least one transimpedance amplifier (TA), being provided with the electrical current signals (I.sub.PD) from the light-receiving component (PD), at least one automatic gain controller (AG) for controlling the gain or transimpedance (R) of the transimpedance amplifier (TA), at least one integrator (IN) in a feedback path (FP), said integrator (IN) generating a control signal (V.sub.int), at least one voltage-controlled current source (CS), being provided with the control signal (V.sub.int) from the integrator (IN), at least one limiter (LI) acting as a comparator and generating in its output a logic level for positive or negative voltages in its input,
and a corresponding method in such a way that a multilevel optical link can be provided, at least one second transimpedance amplifier (TA2) arranged in parallel to the transimpedance amplifier (TA), and at least one automatic offset controller (AO) for setting the voltage (V.sub.offset) for the second transimpedance amplifier (TA2)
are proposed.

In order to further develop a circuit arrangement (CR; CR′) for receiving optical signals (SI) from at least one optical guide (GU), said circuit arrangement (CR; CR′) comprising: at least one light-receiving component (PD) for converting the optical signals (SI) into electrical current signals (I.sub.PD), at least one transimpedance amplifier (TA), being provided with the electrical current signals (I.sub.PD) from the light-receiving component (PD), at least one automatic gain controller (AG) for controlling the gain or transimpedance (R) of the transimpedance amplifier (TA), at least one integrator (IN) in a feedback path (FP), said integrator (IN) generating a control signal (V.sub.int), at least one voltage-controlled current source (CS), being provided with the control signal (V.sub.int) from the integrator (IN), at least one limiter (LI) acting as a comparator and generating in its output a logic level for positive or negative voltages in its input,
and a corresponding method in such a way that a multilevel optical link can be provided, at least one second transimpedance amplifier (TA2) arranged in parallel to the transimpedance amplifier (TA), and at least one automatic offset controller (AO) for setting the voltage (V.sub.offset) for the second transimpedance amplifier (TA2)
are proposed.

An optical detection circuit includes: a first optical detection element having a first anode and a first cathode, the first optical detection element being configured to generate voltage between the first anode and the first cathode due to photoelectromotive force generated in accordance with incident-light quantity; and a first operational amplifier having a first non-inverting input terminal, a first inverting input terminal, and a first output terminal, in which the first non-inverting input terminal is connected to fixed potential, one of the first anode and the first cathode is connected to the first inverting input terminal, and the other of the first anode and the first cathode is connected to the first output terminal.

An optical detection circuit includes: a first optical detection element having a first anode and a first cathode, the first optical detection element being configured to generate voltage between the first anode and the first cathode due to photoelectromotive force generated in accordance with incident-light quantity; and a first operational amplifier having a first non-inverting input terminal, a first inverting input terminal, and a first output terminal, in which the first non-inverting input terminal is connected to fixed potential, one of the first anode and the first cathode is connected to the first inverting input terminal, and the other of the first anode and the first cathode is connected to the first output terminal.

The present disclosure provides a substrate integrated with a passive device and a method for manufacturing the same. The method includes: providing and processing a transparent dielectric layer to obtain the transparent dielectric layer provided with a first connection via therein, with the transparent dielectric layer including a first surface and a second surface which are disposed oppositely; and integrating a passive device, which includes at least an inductor, on the transparent dielectric layer. The integrating a passive device on the transparent dielectric layer includes: forming a first sub-structure on the first surface of the transparent dielectric layer, forming a second sub-structure on the second surface of the transparent dielectric layer, and forming a first connection electrode in the first connection via; and the first sub-structure, the first connection electrode and the second sub-structure are connected to form a coil structure of the inductor.

Systems and methods of laser bias calibration are presented. A preamplifier circuit may include a laser voltage monitor circuit and a laser bias control circuit configured to automatically adjust an output laser bias threshold voltage based on a monitored laser voltage. The laser bias control circuit may include a first differentiator circuit, a second differentiator circuit, and a threshold detection circuit. The preamplifier circuit may be utilized in a heat assisted magnetic recording device.

Systems and methods of laser bias calibration are presented. A preamplifier circuit may include a laser voltage monitor circuit and a laser bias control circuit configured to automatically adjust an output laser bias threshold voltage based on a monitored laser voltage. The laser bias control circuit may include a first differentiator circuit, a second differentiator circuit, and a threshold detection circuit. The preamplifier circuit may be utilized in a heat assisted magnetic recording device.

An amplifier for amplification of an electrical signal comprises an electro-optic (EO) medium for receiving the electrical signal, wherein applying the electrical signal to the EO medium causes a change to an effective index of refraction, a device configured for measuring a light phase change for measuring the change to the effective index of refraction, and a photodetector configured to convert the change to the effective index of refraction into an amplified electrical current output signal.

An amplifier for amplification of an electrical signal comprises an electro-optic (EO) medium for receiving the electrical signal, wherein applying the electrical signal to the EO medium causes a change to an effective index of refraction, a device configured for measuring a light phase change for measuring the change to the effective index of refraction, and a photodetector configured to convert the change to the effective index of refraction into an amplified electrical current output signal.

An electronic circuit includes an isolation amplifier, having a first input terminal receiving an AC-signal and including a linear opto-isolator. The opto-isolator has a first output terminal that provides a unipolar signal having an AC-component proportional to the input signal. The circuit includes a transimpedance receiver with first and second operational amplifiers. The first amplifier has a second output terminal and first and second differential input terminals, with the first differential input terminal receiving and amplifying the unipolar output signal from the first output terminal providing an output signal from the circuit at the second output terminal. The second amplifier is configured as an integrator, having a third output terminal coupled to the second differential input terminal and having third and fourth differential input terminals, with the third differential input terminal receiving the output signal from the second output terminal and the fourth differential input terminal connected to ground.