Ross Parke

Future directions in 980-nm pump lasers: submarine deployment to low-cost watt-class terrestrial pumps

The demands of global bandwidth and distribution are rising rapidly as Internet usage grows. This fundamentally means that more photons are flowing within optical cables. While transmitting sources launches some optical power, the majority of the optical power that is present within modem telecommunication systems originates from optical amplifiers. In addition, modem optical amplifiers offer flat optical gain over broad wavelength bands, thus making possible dense wavelength de-multiplexing (DWDM) systems. Optical amplifier performance, and by extension the performance of the laser pumps that drive them, is central to the future growth of both optical transmission and distribution systems.

Performance and reliability of high-power lasers between 900-990 nm

In conclusion, 100-/spl mu/m broad area InGaAs quantum well lasers for fibre laser pumping with peak cw power exceeding 8 W and high power operating up to 90/spl deg/C have been demonstrated. Preliminary lifetest data suggest that reliable 100-/spl mu/m broad area lasers are possible for power between 1/spl sim/2 watts. These lasers will fulfill the lifetime demand of telecommunication applications because of generous power and temperature margins.

Advances in high-power fiber-coupled laser diodes

We describe advances in the development of high-power diffraction-limited lasers for single- mode fiber-coupled sources. The development of the tapered amplifier has led to the realization of a monolithic MOPA diode laser, which provides up to 3 W cw of single-spatial- mode output power. We further describe the implementation of the MOPA in fiber-coupled architectures that provide up to 1.2 W cw coupled into a single-mode optical fiber and some of the optical considerations unique to devices based on tapered amplifiers.

Monolithic Semiconductor MOPAs: How the Watt Was Won

High power spatially coherent semiconductor lasers have been a goal of diode laser researchers for years. Single-stripe devices are generally limited to a hundred mW of output power, at which point reliability problems associated with the high optical intensity at the output facet begin to limit device performance. The simple solution to the problem of facet power density has been to increase the lateral dimension of the laser facet from 3–4 to hundreds of µm. However, this approach has simply traded one problem, facet degradation, for another: control of the spatial mode.

1.3-W cw diffraction-limited monolithically integrated master oscillator flared amplifier at 860 nm

A high-power monolithically integrated master oscillator flared power amplifier is demonstrated which operates at approximately 860 nm to an output power greater than 1.3 cw with a far field pattern consisting of a single, diffraction-limited lobe.

High-power coherent operation of 2-D monolithically integrated master-oscillator power amplifiers

Two-dimensional monolithically integrated master oscillator power amplifiers have been fabricated that emit in a single longitudinal mode to an output power of 4.5 W.

Grating-coupled surface emitters: sensitivity to length-induced phase variations

The steady-state properties of a two-gain section/three-grating surface-emitting laser are studied theoretically as a function of length-induced phase variations. In particular, the optical length of one gain section is varied with respect to the other by up to one grating period. It is found that several mode hops occur. Although the number of these can be reduced by optimizing the design, stable single-mode laser operation requires control of the optical length of each gain and grating section to better than one wavelength.

Optical characteristics of multiple grating surface-emitting semiconductor lasers

The coherent operation of one-dimensional linear arrays of grating-coupled surface-emitting lasers is experimentally investigated, for different laser designs (gain lengths, grating parameters. For laser arrays with shallow grating teeth and strong interelement coupling, a diffraction-limited far field of 0.012 deg FWHM was obtained from up to six coupled lasers extending over a length of 3.5 mm.