Applications of Single Frequency Blue Lasers

Abstract

Gallium nitride (GaN) sources are becoming a regular part of today's world and are now key devices for lighting infrastructures, communications systems and quantum applications, amongst others. In particular, many applications have seen the shift from LEDs to laser diodes to make use of higher powers, higher bandwidths and increased transmission distances. Laser communication systems are well established, however there are applications where the ability to select a single emitted wavelength is highly desirable, such as quantum atomic clocks or in filtered communication systems. Distributed feedback (DFB) lasers have been realised emitting at a single wavelength where the grating structure is etched into the sidewall of the ridge. The main motivation in developing these lasers is for the cooling of ions in atomic clocks; however their feasibility for optical communications is also explored. Narrow linewidth lasers are desirable and this paper will explore how this is achieved. Data rates in excess of 1 Gbit/s have also been achieved in a directly modulated, unfiltered system. These devices lend themselves towards wavelength division multiplexing and filtered optical communications systems and this will be analysed further in the work presented here.

AM/AM and AM/PM Characterization of a GaN Phase and Amplitude Setting Circuit

“…In particular, when combined, the latter two listed functionalities realize the Phase and Amplitude Setting circuits (PASs), key components in Radio Frequency (RF) front ends, and more specifically, for phased array systems. In addition to millimeter-wave and microwave circuits in high-end electronic systems, GaN has been extensively utilized in the fabrication of optoelectronic devices, such as lasers [11][12][13][14][15], light emitting diodes (LEDs) [16][17][18][19][20][21], and solar cells [22][23][24].…”