Patents by Inventor Hoki Kwon
Hoki Kwon has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7545560Abstract: Distributed Bragg reflector (DBR) with reduced DX centers. A DBR includes an AlAs region. The AlAs region includes essentially homogeneous AlAs. The DBR further includes a A1GaAs region. The AlGaAs region includes alternating thin layers of AlAs and GaAs. The alternating thin layers of AlAs and GaAs are arranged such the the AlGaAs region appears as a layer of A1GaAs with appropriate concentrations of Al and Ga.Type: GrantFiled: October 8, 2004Date of Patent: June 9, 2009Assignee: Finisar CorporationInventor: Hoki Kwon
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Patent number: 7433381Abstract: A long wavelength vertical cavity surface emitting laser having a substrate, a first mirror situated on the substrate, an active region situated on the first mirror, a second mirror situated on the active region. The first mirror may have several pairs of layers with an oxidized layer in one or more pairs of that mirror. The substrate may include InP and the mirror components may be compatible with the InP. The one or more layers in the first mirror may be oxidized via a trench-like approach or other arrangement.Type: GrantFiled: June 25, 2003Date of Patent: October 7, 2008Assignee: Finisar CorporationInventors: Tzu-Yu Wang, Hoki Kwon, Jae-Hyun Ryou, Gyoungwon Park, Jin K. Kim
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Patent number: 7295586Abstract: GaAs(1?x)Sbx layers are grown by MOCVD. For lattice matching with InP, x is set to 0.5, while beneficial alternatives include setting x to 0.23, 0.3, and 0.4. During MOVCD, TMGa (or TEGa), TMSb, and AsH3 (or TBAs) are used to fabricate the GaAs(1?x )Sbx layer. Beneficially, the GaAs(1?x)Sbx layer's composition is controlled by the ratio of As to Sb. The MOCVD growth temperature is between 500° C. and 650° C. The GaAs(1?x)Sbx layer is beneficially doped using CCl4 or CBr4. A heavily doped GaAs(1?x)Sbx layer can be used to form a tunnel junction with n-doped layers of InP, AlInAs, or with lower bandgap materials such as AlInGaAs or InGaAsP. Such tunnel junctions are useful for producing long wavelength VCSELs.Type: GrantFiled: February 21, 2002Date of Patent: November 13, 2007Assignee: Finisar CorporationInventor: Hoki Kwon
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Patent number: 7286584Abstract: A vertical cavity surface emitting laser (VCSEL) structure includes a bottom distributed Bragg reflector (DBR) arranged over a substrate; a metal layer interposed between the bottom DBR and the substrate, wherein the metal layer and bottom DBR form a composite mirror structure. A patterned dielectric layer may be interposed between the metal layer and the bottom DBR to reduce a deleterious chemical reaction between the metal layer and the bottom DBR. The metal layer directly contacts a portion of the bottom DBR to enhance the electrical and thermal conductivity of the VCSEL structure.Type: GrantFiled: December 8, 2004Date of Patent: October 23, 2007Assignee: Finisar CorporationInventors: Tzu-Yu Wang, Jin K. Kim, Hoki Kwon, Gyoungwon Park, Jae-Hyun Ryou
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Patent number: 7054345Abstract: A vertical cavity surface emitting laser having an oxidizable layer oxidized with enhanced lateral oxidation. The oxidation may involve adding oxygen in the form of a fluid, with or without other fluid such as water vapor, in the oxidizing environment, and/or in the layer to be oxidized. This oxidation approach may be used for layers with relatively low aluminum content such as in InP based structures, or with high aluminum content such as in GaAs based structures.Type: GrantFiled: June 27, 2003Date of Patent: May 30, 2006Assignee: Finisar CorporationInventors: Jae-Hyun Ryou, Tzu-Yu Wang, Jin K. Kim, Gyoungwon Park, Hoki Kwon
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Publication number: 20060078026Abstract: Distributed Bragg reflector (DBR) with reduced DX centers. A DBR includes an AlAs region. The AlAs region includes essentially homogeneous AlAs. The DBR further includes a AlGaAs region. The AlGaAs region includes alternating thin layers of AlAs and GaAs. The alternating thin layers of AlAs and GaAs are arranged such the the AlGaAs region appears as a layer of AlGaAs with appropriate concentrations of Al and Ga.Type: ApplicationFiled: October 8, 2004Publication date: April 13, 2006Inventor: Hoki Kwon
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Publication number: 20050243881Abstract: A current confinement layer of a VCSEL is formed by adjusting flow rates of In-, Al-, and As-containing precursors introduced within a deposition chamber. By maintaining a low ratio between the flow rate of the As-containing precursors and the total flow rate of In- and Al-containing precursors (e.g., less than 25, 10, 5, or 1), a current confinement layer, lattice matched to InP and having an enhanced oxidation rate, may be formed.Type: ApplicationFiled: December 30, 2004Publication date: November 3, 2005Inventors: Hoki Kwon, Tzu-Yu Wang, Jae-Hyun Ryou, Jin Kim, Gyoungwon Park
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Publication number: 20050243887Abstract: A VCSEL includes a substrate; a first mirror stack over the substrate; an active region having a plurality of quantum wells over the first mirror stack; and a second mirror stack over the active region, wherein either or both of the first and second mirror stacks include alternating layers of II-VI and III-V compounds, and wherein said II-VI compound is selected from the group consisting of ZnCdSe, ZnSeTe and ZnMgSe, and said III-V compound is selected from the group consisting of InGaAsP, InAlGaAs and InP. Such a mirror stack is especially useful for a long-wavelength VCSEL.Type: ApplicationFiled: April 30, 2004Publication date: November 3, 2005Inventor: Hoki Kwon
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Publication number: 20050243886Abstract: A vertical cavity surface emitting laser (VCSEL) structure includes a bottom distributed Bragg reflector (DBR) arranged over a substrate; a metal layer interposed between the bottom DBR and the substrate, wherein the metal layer and bottom DBR form a composite mirror structure. A patterned dielectric layer may be interposed between the metal layer and the bottom DBR to reduce a deleterious chemical reaction between the metal layer and the bottom DBR.Type: ApplicationFiled: December 8, 2004Publication date: November 3, 2005Inventors: Tzu-Yu Wang, Jin Kim, Hoki Kwon, Gyoungwon Park, Jae-Hyun Ryou
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Patent number: 6901096Abstract: Distributed Bragg reflectors (DBRs), and VCSELs that use such DBRs, comprised of AlP layers on InP substrates. When grown on an InP substrate, if the critical layer thickness (tcrt) of AlP is greater than ?/4nAlP, where nAlP is the index of refraction of InP and ? is the wavelength, then the DBR can be grown using alternating layers of InP and AlP, wherein the thickness of the AlP is less than the critical thickness. If the critical layer thickness (tcrt) of AlP is greater than ?/4nAlP, then the DBR mirror is grown using alternating layers of InP and of an AlP/InP superlattice, wherein the AlP/InP superlattice is comprised of InP and of AlP wherein the thickness of the AlP is less than the critical thickness.Type: GrantFiled: December 20, 2002Date of Patent: May 31, 2005Assignee: Finisar CorporationInventor: Hoki Kwon
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Patent number: 6888873Abstract: A vertical cavity surface emitting laser having an InP substrate and a lower mirror stack comprised of a plurality of alternating layers of AlPSb and GaPSb over the InP substrate. An InP spacer is over the lower mirror stack. An active region is over the InP spacer, and a tunnel junction is over the active region. Then a top mirror structure comprised of a low-temperature formed first GaAs buffer layer, a high-temperature formed second GaAs seed layer, an insulating structure having an opening, and a GaAs/Al(Ga)As mirror stack that is grown by lateral epitaxial overgrowth.Type: GrantFiled: February 21, 2002Date of Patent: May 3, 2005Assignee: Finisar CorporationInventor: Hoki Kwon
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Publication number: 20040264541Abstract: A long wavelength vertical cavity surface emitting laser having a substrate, a first mirror situated on the substrate, an active region situated on the first mirror, a second mirror situated on the active region. The first mirror may have several pairs of layers with an oxidized layer in one or more pairs of that mirror. The substrate may include InP and the mirror components may be compatible with the InP. The one or more layers in the first mirror may be oxidized via a trench-like approach or other arrangement.Type: ApplicationFiled: June 25, 2003Publication date: December 30, 2004Applicant: Honeywell International Inc.Inventors: Tzu-Yu Wang, Hoki Kwon, Jae-Hyun Ryou, Gyoungwon Park, Jin K. Kim
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Publication number: 20040264531Abstract: A vertical cavity surface emitting laser having an oxidizable layer oxidized with enhanced lateral oxidation. The oxidation may involve adding oxygen in the form of a fluid, with or without other fluid such as water vapor, in the oxidizing environment, and/or in the layer to be oxidized. This oxidation approach may be used for layers with relatively low aluminum content such as in InP based structures, or with high aluminum content such as in GaAs based structures.Type: ApplicationFiled: June 27, 2003Publication date: December 30, 2004Applicant: Honeywell International Inc.Inventors: Jae-Hyun Ryou, Tzu-Yu Wang, Jin K. Kim, Gyoungwon Park, Hoki Kwon
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Patent number: 6822995Abstract: A vertical cavity surface emitting laser having a GaAs/Al(Ga)As DBR mirror over an InP layer A first GaAs layer is MOCVD grown on an InP layer at a growth temperature of between 400 and 450° C. Then a second GaAs layer is grown by MOCVD at a growth temperature of about 600° C. over the first GaAs layer. A GaAs/Al(Ga)As DBR mirror is then grown over the second GaAs layer. Beneficially, an insulating layer is disposed between the second GaAs layer and the GaAs/Al(Ga)As DBR mirror. The insulating layer includes an opening that exposes the second GaAs layer. Then the GaAs/Al(Ga)As DBR mirror is grown by lateral epitaxial overgrowth. The lower DBR can be comprised of a material that provides an acceptable lattice match with InP layers. A tunnel junction can be formed over an InP active region.Type: GrantFiled: February 21, 2002Date of Patent: November 23, 2004Assignee: Finisar CorporationInventor: Hoki Kwon
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Publication number: 20040120375Abstract: Distributed Bragg reflectors (DBRs), and VCSELs that use such DBRs, comprised of AlP layers on InP substrates. When grown on an InP substrate, if the critical layer thickness (tcrt) of AlP is greater than &lgr;/4nAlP, where nAlP is the index of refraction of InP and &lgr; is the wavelength, then the DBR can be grown using alternating layers of InP and AlP, wherein the thickness of the AlP is less than the critical thickness. If the critical layer thickness (tcrt) of AlP is greater than &lgr;/4nAlP, then the DBR mirror is grown using alternating layers of InP and of an AlP/InP superlattice, wherein the AlP/InP superlattice is comprised of InP and of AlP wherein the thickness of the AlP is less than the critical thickness.Type: ApplicationFiled: December 20, 2002Publication date: June 24, 2004Inventor: Hoki Kwon
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Publication number: 20030156611Abstract: A vertical cavity surface emitting laser having a GaAs/Al(Ga)As DBR mirror over an InP layer A first GaAs layer is MOCVD grown on an InP layer at a growth temperature of between 400 and 450° C. Then a second GaAs layer is grown by MOCVD at a growth temperature of about 600° C over the first GaAs layer. A GaAs/Al(Ga)As DBR mirror is then grown over the second GaAs layer. Beneficially, an insulating layer is disposed between the second GaAs layer and the GaAs/Al(Ga)As DBR mirror. The insulating layer includes an opening that exposes the second GaAs layer. Then the GaAs/Al(Ga)As DBR mirror is grown by lateral epitaxial overgrowth. The lower DBR can be comprised of a material that provides an acceptable lattice match with InP layers. A tunnel junction can be formed over an InP active region.Type: ApplicationFiled: February 21, 2002Publication date: August 21, 2003Inventor: Hoki Kwon
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Publication number: 20030156616Abstract: A vertical cavity surface emitting laser having an InP substrate and a lower mirror stack comprised of a plurality of alternating layers of AlPSb and GaPSb over the InP substrate. An InP spacer is over the lower mirror stack. An active region is over the InP spacer, and a tunnel junction is over the active region. Then a top mirror structure comprised of a low-temperature formed first GaAs buffer layer, a high-temperature formed second GaAs seed layer, an insulating structure having an opening, and a GaAs/Al(Ga)As mirror stack that is grown by lateral epitaxial overgrowth.Type: ApplicationFiled: February 21, 2002Publication date: August 21, 2003Inventor: Hoki Kwon
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Publication number: 20030156610Abstract: GaAs(1−x)Sbx layers are grown by MOCVD. For lattice matching with InP, x is set to 0.5, while beneficial alternatives include setting x to 0.23, 0.3, and 0.4. During MOVCD, TMGa (or TEGa), TMSb, and AsH3 (or TBAs) are used to fabricate the GaAs(1−x )Sbx layer. Beneficially, the GaAs(1−x)Sbx layer's composition is controlled by the ratio of As to Sb. The MOCVD growth temperature is between 500° C. and 650° C. The GaAs(1−x)Sbx layer is beneficially doped using CCl4 or CBr4. A heavily doped GaAs(1−x)Sbx layer can be used to form a tunnel junction with n-doped layers of InP, AlInAs, or with lower bandgap materials such as AlInGaAs or InGaAsP. Such tunnel junctions are useful for producing long wavelength VCSELs.Type: ApplicationFiled: February 21, 2002Publication date: August 21, 2003Inventor: Hoki Kwon