Towards high-order modulation using complex modulation of semiconductor lasers

Power Supply and Current Modulation Circuits for Semiconductor Lasers

Design and construction of a stable current supply with protection circuits are described. The reported circuit provides a high-stable and high-level current variable from 0.5-1.2 A with the protect ion circuits to prevent over load current, voltage and off-range temperature operation. A detailed analysis of the circuit parameters is given and the time behaviors of the load voltage/current and ...

Experimental method based on wavelength-modulation spectroscopy for the characterization of semiconductor lasers under direct modulation.

An experimental method is presented for characterization of the combined intensity and frequency modulation produced when the injection current of a laser diode is modulated. The reported technique is based on the analysis of the harmonic signals produced when a modulated laser is used to probe a gas absorption line by the so-called wavelength-modulation spectroscopy method. Based on a theoreti...

Enhanced Modulation and Noise Characteristics in 1.55 µm QD Lasers using Additional Optical Pumping

The modulation response, relative intensity noise (RIN) and frequency noise (FN) characteristics of quantum dot (QD) lasers are investigated theoretically in the presence of an external optical beam. Using small signal analysis of the rate equations for carriers and photons, it is demonstrated that by injecting excess carriers into the QDs excited state through optical pumping, the modulation r...

Optical ASK and FSK Modulation By Using Quantum Well Transistor Lasers

In this paper, transistor lasers (TLs) are used as an optical modulator for generation of ASK(Amplitude Shift Keying) and FSK (Frequency Shift Keying) optical signals. Our analysis is based on continuity equation, rate equations, and the theory of discontinuity of quasi-fermi level at the abrupt junction. Our simulation results indicate that, the specification of ASK and FSK optical signals, ar...

High-speed Modulation of Semiconductor Lasers and Properties of Silver-coated Quantum-dot Lasers by Andrew J. Millard