| 1. |
- Asplund, C., et al.
(författare)
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Doping-induced losses in AlAs/GaAs distributed Bragg reflectors
- 2001
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 90:2, s. 794-800
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Tidskriftsartikel (refereegranskat)abstract
- We have studied n- and p-type doping-induced performance degradation of AlAs/GaAs distributed Bragg reflectors (DBRs) for applications in vertical cavity lasers (VCLs). Based on high-accuracy optical reflectance and triple-axis x-ray diffraction measurements on a variety of differently doped DBR structures grown by metalorganic vapor-phase epitaxy, a fitting procedure was employed to extract the doping-dependent optical loss. A striking observation is that the reflectance of these DBRs is much more sensitive to n- than p-type doping incorporation. While in the latter case the loss can be well accounted for by intervalence-band and free-carrier absorption, additional loss mechanisms must be considered for n-type DBRs. We relate the losses to doping-enhanced interdiffusion effects resulting in increased interface scattering. These findings should have important consequences for the design of VCLs, demonstrating the importance of reduced n-type doping concentrations and/or growth temperatures, or the application of alternative device concepts, e.g., employing intracavity contacts.
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| 2. |
- Mogg, S., et al.
(författare)
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Absolute reflectance measurements by a modified cavity phase-shift method
- 2002
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 73:4, s. 1697-1701
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Tidskriftsartikel (refereegranskat)abstract
- This article reports on a modified cavity phase-shift (CAPS) method for accurate and reliable characterization of high reflectance mirrors. Our approach relies on using a directly modulated Fabry-Perot laser to circumvent the difficulties encountered in previous attempts with the CAPS method. The Fabry-Perot laser diode ensures a constant coupling between the probe laser and test cavity modes. This results in a stable beam intensity transmitted through the test cavity allowing for accurate measurements of the phase shift from which the absolute reflectance can be determined. The experimental arrangement presented in this article is versatile and easy to use. The method is nondestructive and especially suited for the characterization of distributed Bragg reflectors (DBRs) employed in vertical-cavity optoelectronic devices. A premium feature of this method is its capability to probe a relatively small area of less than 1 mm which can be positioned anywhere across the surface of the wafer. We demonstrate the use of the method by measuring the absolute reflectance of metalorganic vapor-phase epitaxy grown AlAs/GaAs DBRs for 1.3 mum vertical-cavity lasers.
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| 3. |
- Mogg, S., et al.
(författare)
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High-performance 1.2-ÎŒm Highly strained InGaAs/GaAs quantum well lasers
- 2002
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Ingår i: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - Stockholm. ; , s. 107-110
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Konferensbidrag (refereegranskat)abstract
- The growth and characterisation of high-performance 1.2-Όm highly strained InGaAs/GaAs single quantum well (SQW) laser diodes is reported. High output power in excess of 200 mW per facet was obtained from ridge-waveguide (RWG) lasers at an emission wavelength of 1230 nm. These lasers operate CW to at least 145°C and show a high characteristic temperature of 150 K. The net modal gain was measured using the method described by Hakki and Paoli.
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| 4. |
- Mogg, Sebastian, et al.
(författare)
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High-performance 1.2- mu;m highly strained InGaAs/GaAs quantum well lasers
- 2002
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Ingår i: Indium Phosphide and Related Materials Conference, 2002. IPRM. 14th. ; , s. 107-110
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Konferensbidrag (refereegranskat)abstract
- The growth and characterisation of high-performance 1.2- mu;m highly strained InGaAs/GaAs single quantum well (SQW) laser diodes is reported. High output power in excess of 200 mW per facet was obtained from ridge-waveguide (RWG) lasers at an emission wavelength of 1230 nm. These lasers operate CW to at least 145 deg;C and show a high characteristic temperature of 150 K. The net modal gain was measured using the method described by Hakki and Paoli (1975).
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| 5. |
- Mogg, S., et al.
(författare)
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n-type doping induced losses in 1.3/1.55 ÎŒm distributed Bragg reflectors
- 2000
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Ingår i: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - Williamsburg, VA, USA. ; , s. 388-391
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Tidskriftsartikel (refereegranskat)abstract
- The effect of n-type doping on the peak reflectivity of InGaAsP/InP as well as GaAs/AlAs distributed Bragg reflectors for long-wavelength vertical-cavity lasers has been investigated. A variety of mirrors with different doping levels were grown in both material systems using metal organic vapour phase epitaxy. The reflectance of the structures was measured with high accuracy employing two independent measurement techniques. While nominally undoped DBRs exhibit an expected reflectivity in excess of 99.9%, doping is found to induce significant losses resulting in up to 0.6% reduced reflectance.
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| 6. |
- Plaine, G. Y., et al.
(författare)
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Low-temperature metal-organic vapor-phase epitaxy growth and performance of 1.3-mu m GaInNAs/GaAs single quantum well lasers
- 2002
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Ingår i: Japanese Journal of Applied Physics. - 0021-4922 .- 1347-4065. ; 41:2B, s. 1040-1042
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Tidskriftsartikel (refereegranskat)abstract
- GaInNAs/GaAs quantum-well (Q V) lasers emitting at 1.3 mum. were grown using metal-organic vapor-phase epitaxy (MOVPE) in the limit of very low growth rate and temperature. The material was characterized by photoluminescence (PL) Spectroscopy as well as by implementation in broad-area (BA) edge-emitting lasers. While the PL intensity was found to decrease by more than two orders of magnitude between 1175 and 1350 mn, the corresponding BA laser threshold current showed a much more modest increase. For a 1.28-mum laser the threshold current was 1.2 kA/cm(2) (1200 pin long devices), with a slope efficiency 0.24 W/A per facet and T-0 = 100 K. Comparison between PL emission properties and BA laser performance revealed a complex relationship. A high PL intensity does not necessarily lead to low threshold-current lasers. In these cases, the FWHM seems to be the more relevant parameter for QW optimization.
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