| 1. |
- Haglund, Erik, 1985, et al.
(författare)
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Demonstration of post-growth wavelength control of VCSELs using high-contrast gratings
- 2015
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Ingår i: HP Laboratories Technical Report. ; 70
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate post-growth wavelength setting of vertical-cavity surface-emitting lasers (VCSELs) using high-contrast gratings (HCGs). By fabricating HCGs with different duty-cycle and period, the HCG reflection phase can be varied, in effect giving different optical cavity lengths for HCGVCSELs with different grating parameters. This enables fabrication of monolithic multi-wavelength HCG-VCSEL arrays for wavelength-division multiplexing (WDM). The GaAs HCG is suspended in air by selective removal of an InGaP sacrificial layer. Electrically injected 980-nm HCGVCSELs with sub-mA threshold currents indicate high reflectivity from the GaAs HCGs. Lasing over a wavelength span of 15 nm was achieved, enabling a 4-channel WDM array with 5 nm channel spacing. Device design, fabrication and experimental proof-of-concept are presented.
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| 2. |
- Haglund, Erik, 1985, et al.
(författare)
-
Demonstration of post-growth wavelength setting of VCSELs using high-contrast gratings
- 2016
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Ingår i: Optics Express. - : The Optical Society. - 1094-4087 .- 1094-4087. ; 24:3, s. 1999-2005
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate, for the first time, post-growth wavelength setting of electrically-injected vertical-cavity surface-emitting lasers (VCSELs) by using high-contrast gratings (HCGs) with different grating parameters. By fabricating HCGs with different duty cycle and period, the HCG reflection phase can be varied, in effect giving different optical cavity lengths for HCG-VCSELs with different grating parameters. This enables fabrication of monolithic multi-wavelength HCG-VCSEL arrays for wavelength-division multiplexing (WDM). The GaAs HCG is suspended in air by removing a sacrificial layer of InGaP. Electrically-injected 980-nm HCG-VCSELs with sub-mA threshold currents indicate high reflectivity from the GaAs HCGs. Lasing over a wavelength span of 15 nm was achieved, enabling a 4-channel WDM array with 5 nm channel spacing. A large wavelength setting span was enabled by an air-coupled cavity design and the use of only the HCG as top mirror.
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| 3. |
- Haglund, Erik, 1985, et al.
(författare)
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GaAs High-Contrast Gratings with InGaP Sacrificial Layer for Multi-Wavelength VCSEL Arrays
- 2016
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Ingår i: Conference Digest - IEEE International Semiconductor Laser Conference. - 0899-9406. - 9784885523069 ; TuD2, s. Article n0 7765746-
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Konferensbidrag (refereegranskat)abstract
- We report on highly reflective suspended GaAs high-contrast gratings (HCGs) using an InGaP sacrificial layer. A high reflectivity approaching 100% was observed both in direct reflectivity measurement and by low threshold currents in fabricated multi-wavelength HCG-VCSEL arrays.
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| 4. |
- Haglund, Erik, 1985, et al.
(författare)
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Multi-wavelength VCSEL arrays using high-contrast gratings
- 2017
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9781510606678 ; 10113
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Konferensbidrag (refereegranskat)abstract
- The use of a high-contrast grating (HCG) as the top mirror in a vertical-cavity surface-emitting laser (VCSEL) allows for setting the resonance wavelength by the grating parameters in a post-epitaxial growth fabrication process. Using this technique, we demonstrate electrically driven multi-wavelength VCSEL arrays at ∼980 nm wavelength. The VCSELs are GaAs-based and the suspended GaAs HCGs were fabricated using electron-beam lithography, dry etching and selective removal of an InGaP sacrificial layer. The air-coupled cavity design enabled 4-channel arrays with 5 nm wavelength spacing and sub-mA threshold currents thanks to the high HCG reflectance.
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| 5. |
- Haglund, Erik, 1985, et al.
(författare)
-
Wavelength Control of VCSELs using High-Contrast Gratings
- 2017
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Ingår i: VII Workshop on Physics and Technology of Semiconductor Lasers.
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Konferensbidrag (refereegranskat)abstract
- The vertical-cavity surface-emitting laser (VCSEL) is a well-established light source for sensing and short-reach optical links. The surface emission allows wafer-scale testing enabling low-cost manufacturing, while the VCSELs’ small modal volume leads to low power consumption, high-speed modulation at small currents, and small footprint [1]. Conventional VCSELs consist of an active region sandwiched between two distributed Bragg reflectors (DBRs). Replacing the top DBR with a high-contrast grating reflector offers unique possibilities to engineer and control VCSEL emission wavelength and modal properties [2,3]. A high-contrast grating (HCG) is typically formed by bars of high refractive index suspended in air. HCGs with certain grating parameters (duty cycle, period, and thickness) can function as ultra-thin reflectors with close to 100% reflectivity [4]. Besides the reflectivity, the grating parameters also influence the reflection phase. This enables fabrication of multi-wavelength VCSEL arrays by fabricating HCG-VCSELs with different grating parameters. In order to utilize the extraordinary properties of the HCG, the VCSEL mode must be sensitive to the HCG, which leads to complicated cavity configurations with coupled cavity effects and low optical confinement. This talk will summarize experimental work performed at Chalmers University of Technology in collaboration with Hewlett Packard Enterprise. The design of HCGs and HCG-VCSELs will be presented as well as experimental results from 980 nm HCG-VCSELs and demonstration of post-growth wavelength setting for wavelength-division multiplexing (WDM) VCSEL arrays [5].References[1]Larsson, “Advances in VCSELs for communication and sensing,” IEEE J. Sel. Top. Quantum Electron. 17(6), 1552-1567 (2011).[2]V. Karagodsky, et al., ”Monolithically integrated multi-wavelength VCSEL arrays using high-contrast gratings”, Opt. Express 18(2), 694-699 (2010).[3]S. Inoue, et al., “Highly angular dependent high-contrast grating mirrors and its application for transverse-mode control of VCSELs”, Jpn. J. Appl. Phys. 53, 090306 (2014).[4]C. J. Chang-Hasnain et al., “High-contrast gratings for integrated optoelectronics”, Adv. Opt. Photon. 4, 379-, (2012).[5]E. Haglund, et al., “Demonstration of post-growth wavelength-setting of VCSELs using high-contrast gratings”, Opt, Express 24(3), 1999-2005 (2016).AcknowledgementThis work was been supported by Hewlett Packard Enterprise (HPE), the Swedish Foundation for Strategic Research (SSF) and the Swedish Research Council (VR). The epitaxial material was provided by IQE Europe.
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