R. Menna

1400 - 1480 nm ridge-waveguide pump lasers with 1 watt CW output power for EDFA and Raman amplification

High power ridge-waveguide (RWG) lasers with emission wavelengths from 1400 to 1480 nm have been developed to meet the demands of high channel density EDFA and Raman amplification systems. Output power levels as high as 1 watt from the RWG device can be effectively coupled to single-mode optical fiber producing ex-fiber powers as high as 710 mW.

High power 1550 nm distributed feedback lasers with 440 mW CW output power for telecommunication applications

Summary form only given. High power 1550 nm InGaAsP/InP single-frequency distributed-feedback lasers with record output powers are reported. Ex-facet power levels of 440 mW and single-mode fiber power of 340 mW have been achieved for CW operation at 20/spl deg/C.

High power InGaAsP/InP broad-waveguide single-mode ridge-waveguide lasers

Single-mode broad-waveguide separate confinement ridge-waveguide InGaAsP/InP diode lasers emitting in 1500 nm wavelength range have realized cw output power levels in excess of 400 mW. The high-power broad-waveguide structure design and ridge-waveguide fabrication technology along with device operational performance parameters will be discussed.

High power single spatial and longitudinal mode 1310 nm InGaAsP/InP lasers with 450 mW CW output power for telecommunication applications

High power 1310 nm InGaAsP/InP Fabry-Perot and single-frequency distributed-feedback (DFB) lasers with record output powers are reported. DFB chip power levels of 450 mW and ex-fiber power of 315 mW have been achieved for CW operation at 20/spl deg/C.

Waveguide collapse In InGaAsP ridge-waveguide lasers with weak lateral optical confinement

Summary form only given. The maximum CW powers for single-mode diode lasers are limited by tolerable current and photon densities in their active regions. The maximum width of a single-mode laser active region is inversely proportional to /spl radic//spl Delta/n/sub B/, where /spl Delta/n/sub B/ is the built-in refractive index step at the active region boundary. In this paper, /spl lambda/=1.5 /spl mu/m InGaAsP/InP SCH 3QW broad-waveguide (600 nm) ridge waveguide lasers with low values of /spl Delta/n/sub B/ (5 - 7/spl times/10/sup -3/) have been investigated.

14xx nm DFB InGaAsP/InP pump lasers with 500 mW CW output power for WDM combining

In conclusion, we have demonstrated 14xx nm DFB pump InGaAsP/InP ridge waveguide lasers with a record CW chip power level of 500 mW and ex-fiber or module power of 300 mW. Narrow emission line with very weak current/temperature peak position dependence allows us to use conventional wavelength multiplexing techniques to combine output of DFB pumps with different wavelengths into one SM fiber. Outputs from two 14xx nm DFB lasers with wavelengths differing by 16 nm have been combined in one SM fiber with efficiencies close to 90%, thereby producing a total 14xx nm power level of 500 mW.

High Power 1300 nm Fabry-Perot and DFB Ridge Waveguide Lasers

In this paper we summarize the results on the development of high power 1300 nm ridge waveguide Fabry-Perot and distributed-feedback (DFB) lasers. Improved performance of MOCVD grown InGaAsP/InP laser structures and optimization of the ridge waveguide design allowed us to achieve more than 800 mW output power from 1300 nm single mode Fabry-Perot lasers. Despite the fact that the beam aspect ratio for ridge lasers (30 degree(s) x 12 degree(s)) is higher than that for buried devices, our modeling and experiments demonstrated that the fiber coupling efficiency of about 75-80% could be routinely achieved using a lensed fiber or a simple lens pair. Fiber power of higher than 600 mW was displayed. Utilizing similar epitaxial structures and device geometry, the 1300 nm DFB lasers with output power of 500 mW have been fabricated. Analysis of the laser spectral characteristics shows that the high power DFB lasers can be separated into several groups. The single frequency spectral behavior was exhibited by about 20% of all studied DFB lasers. For these lasers, side-mode suppression increases from 45 dB at low current up to 60 dB at maximum current. About 30% of DFB lasers, at all driving currents, demonstrate multi-frequency spectra consisting of 4-8 longitudinal modes with mode spacing larger than that for Fabry-Perot lasers of the same cavity length. Both single frequency and multi frequency DFB lasers exhibit weak wavelength-temperature dependence and very low relative intensity noise (RIN) values. Fabry-Perot and both types of DFB lasers can be used as pump sources for Raman amplifiers operating in the 1300 nm wavelength range where the use of EDFA is not feasible. In addition, the single-mode 1300 nm DFB lasers operating in the 500 mW power range are very attractive for new generation of the cable television transmission and local communication systems.

Packing techniques to increase wavelength tuning of distributed feedback lasers

Summary form only given. Distributed feedback (DFB) diode lasers are used as sources in laser absorption spectrometers for trace gas analysis. Many molecules, including common environmental pollutants and toxic chemicals, have absorption bands between 760 nm and 2004 nm. These bands are strong enough to allow detection at or below the parts-per-million (ppm) level. In order to sweep through an absorption peak a wavelength tuning range of over one wave number is typically required. In FM spectroscopy the wavelength of the laser is tuned with temperature close to the absorption peak. A low-frequency (ranging from a few Hz to 1 kHz) saw tooth current ramp is then applied to the diode laser that repetitively sweeps its emission frequency across the absorption peak. One needs as high as possible a current tuning rate for as small as possible a current change to minimize power changes and non-linearity.

2.0 - 2.4 /spl mu/m High-Power Broaden Waveguide SCH-QW InGaAsSb/AIGaAsSb Diode Lasers

By controlling tlic quantum well wtdths and the tunnelling barrier thickness of hcterastructures it i s posrible to create artificial potentials where level separations, dipole matrix dements, lifetimes and seanenng times are dependent on the potential design. This allows us to conceive new materials (mierral by dedgn) where electronic and optical properties cnn h tailored not only far demonstrate new physical effects but also to oplimise device performance. The Quantum Cascade (QC) laser is an excellent example of how quantum engineering can be used to design and develop new laser material in the mid-ir. After the first demonstration of Quantum cascade lasers a strong effort has been done to improve the performance of thi. mid-ir source which is now ready to be exploited into sensing systems for molecular detection in Ihe atmospheric windows (3 5 pm and 8 13 tun). Room temperature operation., high peak pow& and DFB lasers4 have been demonstrated, making this laser the first room tempera& mid-ir coherent semiconductor source operating single mode in the 5 .9 pm mnge. The material system m which the QC h a been demonstrated and developed is InGaAs/InAIAs grown lattice matched on InP. There are few advantages related to this IhetemmctuIe namely the higher conduction band discontinuit) (deeper quantum well) and the low refractive index substrate which can be uacd as lower cladding. Nevenheless a strong effort i s underway also in the GaAdAIGaA5 systcm. The la t te~ is the most developed material system (at present represents about 80% of the voiume d the Ill-V market) and can offer more degree of freedom in the quanmiii dasign by vvrying the aluminium concenimtion or hy adding thin GalnA~ strained layers. Recent results on both material systems will be presented with a emphasis on thc new quantum S ~ I U C ~ U I ~ S on GaAslAIGaAs. In conciurion new concepa and experimental results for semiconductor laser waveguide based on surface plasmon at metal-ddearie interface will be discussed.