1. A microbial transformation process for producing a hydroxyaromatic compound represented by the formula (II):
6
wherein R1 represents a carboxyl group, a C2-5 alkoxy-carbonyl group, a hydroxyl group, a nitro group, a cyano group or a C1-5 alkyl group, m represents an integer of 1 to 5, n represents an integer of 0 to 5, p represents an integer of 1 to 3, m, n and p satisfy a relation of mn42p, and when n is 2 or more, R1 may be the same or different from each other, which comprises bringing an aromatic sulfonic acid compound represented by the formula (I):
7
wherein each of R1, m, n and p has the same meaning as defined above, and M represents a hydrogen atom, an alkali metal, an alkaline earth metal or a C1-5 alkyl group, in contact with a culture medium, cells or treated cells of a microorganism belonging to Ochrobactrum genus.
2. The process for producing a hydroxyaromatic compound according to claim 1, wherein R1 is a carboxyl group or a C2-5 alkoxycarbonyl group, and p is 1.
3. The process for producing a hydroxyaromatic compound according to claim 2, wherein n is 2 and m is 1.
4. The process for producing a hydroxyaromatic compound according to claim 1, wherein the aromatic sulfonic acid compound represented by the formula (I) is a compound selected from the group consisting of benzenesulfonic acid sodium salt, 1-naphthalenesulfonic acid sodium salt and 5-sulfonaphthalic acid sodium salt.
5. The process for producing a hydroxyaromatic compound according to claim 3, wherein the compound represented by the formula (I) is 5-sulfoisophthalic acid sodium salt and the compound represented by the formula (II) is 5-hydroxyiso-phthalic acid.
6. The process for producing a hydroxyaromatic compound according to any one of claims 1 to 4, wherein the microorganism belonging to Ochrobactrum genus is Ochrobactrum anthropi.
7. The process for producing a hydroxyaromatic compound according to claim 6, wherein Ochrobactrum anthropi is Ochrobactrum anthropi S9 deposited under a receipt number of FERM BP-7546.
8. The process for producing a hydroxyaromatic compound according to claim 1, wherein the process is carried out by
(a) a method wherein microorganisms are cultured in a culture medium containing the compound represented by the formula (1) as a substrate;
(b) a method wherein the microorganisms are collected from a culture medium where they were cultured and brought into contact with the compound represented by the formula (1); or
(c) a method wherein a cell-free extract prepared from the cells of the microorganisms are brought into contact with the compound represented by the formula (1).
9. The process for producing a hydroxyaromatic compound according to claim 8, wherein culture is conducted under an aerobic condition by using an aerobic culture method at a temperature in the range of 20 to 30 C.
10. The process for producing a hydroxyaromatic compound according to claim 8, wherein the method (a) is carried out by culturing the microorganisms with addition of the compound represented by the formula (1) by adding at a point where an hydroxylation activity of transforming microorganisms starts to elevate.
11. The process for producing a hydroxyaromatic compound according to claim 8, wherein the compound represented by the formula (1) is added 1 to 5 days after the start of culturing the transforming microorganisms in an amount in the range of 0.01 to 5.0% based on the medium.
12. The process for producing a hydroxyaromatic compound according to claim 11, wherein the amount of the compound represented by the formula (1) is in the range of 0.025 to 0.5% based on the medium.
13. The process for producing a hydroxyaromatic compound according to claim 8, wherein the method (b) is carried out by culturing transforming microorganisms in the presence of a little amount of a substrate until an hydroxylation activity of the transforming microorganisms is maximized.
14. The process for producing a hydroxyaromatic compound according to claim 13, wherein culture is carried out for 2 or 3 days after the start of culture, and then, the transforming microorganisms are brought into contact with a starting compound in an aqueous solvent of a 10 to 100 mM phosphate buffer of pH 5 to 9 at a temperature of 20 to 33 C. and a concentration of the substrate in the range of 0.01 to 5.0% based on the culture medium for 1 to 8 days.
15. The process for producing a hydroxyaromatic compound according to claim 8, wherein the cell-free extract used in the method (c) is obtained by applying a physical or chemical means to the microorganisms to give a product in a form of crushed cells by trituration or ultrasonic treatment, or in a form of a dissolved solution of the cells by treating with an organic solvent, a surfactant or an enzyme.
16. Ochrobactrum anthropi S9 which is deposited under a receipt number of FERM BP-7546.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A phase modulation waveguide structure comprising:
one of a semiconductor and a semiconductor-on-insulator substrate;
a doped semiconductor layer formed over the one of a semiconductor and a semiconductor-on-insulator substrate, said doped semiconductor layer comprising a waveguide rib protruding from a surface thereof not in contact with the one of a semiconductor and a semiconductor-on-insulator substrate; and
an electrical contact on top of the waveguide rib, said electrical contact being formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the waveguide rib and the electrical contact and lower than the optical refractive index of the doped semiconductor layer,
wherein during propagation of an optical mode within the waveguide structure, the electrical contact isolates the optical mode between the doped semiconductor layer and a metal electrode contact on top of said electrical contact.
2. The phase modulation waveguide structure according to claim 1, wherein the electrical contact comprises at least one selected from the group of: an Indium Tin Oxide (ITO) material, a CNT material, and metamaterials including arrays of CNTs.
3. The phase modulation waveguide structure according to claim 1, wherein the doped semiconductor layer is a doped Silicon (Si) layer.
4. The phase modulation waveguide structure according to claim 1,
wherein the phase modulation waveguide structure further comprises a thin gate oxide layer between the waveguide rib and the electrical contact, the thin gate oxide layer being in contact with both the waveguide rib and the electrical contact, and
wherein the thin gate oxide layer not only is on top of the waveguide rib but also on sidewalls and shoulder regions thereof.
5. The phase modulation waveguide structure according to claim 4, wherein the electrical contact is formed over the thin gate oxide layer by at least one of: a Chemical Vapor Deposition (CVD) and a sputtering process.
6. The phase modulation waveguide structure according to claim 1, wherein the phase modulation waveguide structure further comprises another metal electrode contact on a highly doped region of the doped semiconductor layer, said metal electrode contact being of an opposite polarity of the metal electrode contact on top of the electrical contact.
7. The phase modulation waveguide structure according to claim 1, wherein the electrical contact on top of the waveguide rib is extended in a lateral direction thereof away from the position of the waveguide rib, and the metal electrode contact is on top of the lateral extension of the electrical contact.
8. The phase modulation waveguide structure according to claim 1,
wherein the waveguide rib is doped such that predominant charge carriers in the waveguide rib are complementary to predominant charge carriers in lateral portions of the doped semiconductor layer,
wherein the waveguide rib forms two PN junctions with lateral portions of the doped semiconductor layer, the PN junctions being formed by sidewalls of the waveguide rib in contact with a sidewall each of said lateral portions of the doped semiconductor layer, and
wherein the electrical contact on top of the waveguide rib directly contacts the waveguide rib.
9. The phase modulation waveguide structure according to claim 8, wherein the phase modulation waveguide structure further comprises another metal electrode contact on a highly doped region of a lateral portion of the doped semiconductor layer, said metal electrode contact being of an opposite polarity of the metal electrode contact on top of the electrical contact.
10. The phase modulation waveguide structure according to claim 1,
wherein the waveguide rib is doped such that predominant charge carriers in the waveguide rib are complementary to predominant charge carriers in the doped semiconductor layer from which the waveguide rib protrudes,
wherein the waveguide rib forms a PN junction with a surface boundary of the doped semiconductor layer by contacting said doped semiconductor layer at said surface boundary not in contact with the one of a semiconductor and a semiconductor-on-insulator substrate, said surface boundary being parallel to a surface boundary of the doped semiconductor layer in contact with the one of a semiconductor and a semiconductor-on-insulator substrate, and
wherein the electrical contact on top of the waveguide rib directly contacts the waveguide rib.
11. The phase modulation waveguide structure according to claim 10, wherein the electrical contact on top of the waveguide rib is extended in a lateral direction thereof away from the position of the waveguide rib, and the metal electrode contact is on top of the lateral extension of the electrical contact.
12. The phase modulation waveguide structure according to claim 10, wherein the phase modulation waveguide structure further comprises another metal electrode contact on a highly doped region of the doped semiconductor layer, said metal electrode contact being of an opposite polarity of the metal electrode contact on top of the electrical contact.
13. The phase modulation waveguide structure according to claim 10, wherein the doped semiconductor layer is first doped by ion implantation, followed by epitaxially growing the waveguide rib with opposite doping on top of the doped semiconductor layer.
14. The phase modulation waveguide structure according to claim 1, wherein the phase modulation waveguide structure is built into at least one of: a Mach-Zender Interferometer (MZI) and a ring resonator.
15. A quantum well device for intensity modulation comprising:
a first doped semiconductor alloy layer grown on a semiconductor substrate;
a quantum well structure comprising an undoped semiconductor alloy quantum well layer sandwiched between a second doped semiconductor alloy layer of a same material and a doping as the first doped semiconductor alloy layer and a third doped semiconductor alloy layer of the same material and opposite doping as the first doped semiconductor alloy layer, the second doped semiconductor alloy layer contacting the first doped semiconductor alloy layer and being on top of the first doped semiconductor alloy layer; and
an electrical contact on top of the quantum well structure, said electrical contact being formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the quantum well structure and the electrical contact and lower than the optical refractive index of the doped semiconductor alloy layers,
wherein when a voltage is applied across the second doped semiconductor alloy layer and the third doped semiconductor alloy layer, an electric field and an optical absorption inside the undoped semiconductor alloy quantum well layer are changed, thereby modulating field intensity passing through said undoped semiconductor alloy quantum well layer.
16. The quantum well device according to claim 14, wherein a constituent semiconductor alloy material for all semiconductor alloy layers, including the semiconductor alloy quantum well layer, is SiGe.
17. The quantum well device according to claim 14, wherein a first electrodic contact is made on top of the electrical contact and a second electrodic contact is made on top of the first doped semiconductor alloy layer.
18. The quantum well device according to claim 16, wherein the electrical contact on top of the quantum well structure is extended in a lateral direction thereof away from the position of the quantum well structure, and the first electrodic contact is made on top of the lateral extension of the electrical contact.
19. The quantum well device according to claim 14, wherein the electrical contact comprises at least one selected from the group of: an Indium Tin Oxide (ITO) material, a CNT material, and metamaterials including arrays of CNTs.
20. The quantum well device according to claim 14, wherein the quantum well structure and the first doped semiconductor alloy layer are epitaxially grown on the semiconductor substrate.
21. A method of improving electrical connectivity and minimizing optical loss in a photonic waveguide structure, the method comprising:
providing an electrical contact on top of a semiconductor photonic waveguide, said electrical contact being formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the semiconductor waveguide and the electrical contact and lower than the optical refractive index of constituent semiconductor layers,
wherein the electrical contact minimizes optical loss by isolating a propagating optical mode between a core of the semiconductor waveguide and a metal electrode contacting said electrical contact.
22. The method according to claim 21, wherein the method comprises providing an electrical contact comprising at least one selected from the group of: an Indium Tin Oxide (ITO) material, a CNT material, and metamaterials including arrays of CNTs.
23. A communication link between processor cores comprising:
a high-speed modulator comprising:
a phase modulation waveguide structure comprising:
one of a semiconductor and a semiconductor-on-insulator substrate;
a doped semiconductor layer formed over the one of a semiconductor and a semiconductor-on-insulator substrate, said doped semiconductor layer comprising a waveguide rib protruding from a surface thereof not in contact with the one of a semiconductor and a semiconductor-on-insulator substrate; and
an electrical contact on top of the waveguide rib, said electrical contact being formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the waveguide rib and the electrical contact and lower than the optical refractive index of the doped semiconductor layer,
wherein during propagation of an optical mode within the waveguide structure, the electrical contact isolates the optical mode between the doped semiconductor layer and a metal electrode contact on top of said electrical contact.
24. The communication link according to claim 23, wherein the electrical contact comprises at least one selected from the group of: an Indium Tin Oxide (ITO) material, a CNT material, and metamaterials including arrays of CNTs.
25. A communication link between processor cores comprising:
a high-speed modulator comprising:
a quantum well device comprising:
a first doped semiconductor alloy layer grown on a semiconductor substrate;
a quantum well structure comprising an undoped semiconductor alloy quantum well layer sandwiched between a second doped semiconductor alloy layer of a same material and a doping as the first doped semiconductor alloy layer and a third doped semiconductor alloy layer of the same material and opposite doping as the first doped semiconductor alloy layer, the second doped semiconductor alloy layer contacting the first doped semiconductor alloy layer and being on top of the first doped semiconductor alloy layer; and
an electrical contact on top of the quantum well structure, said electrical contact being formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the quantum well structure and the electrical contact and lower than the optical refractive index of the doped semiconductor alloy layers,
wherein when a voltage is applied across the second doped semiconductor alloy layer and the third doped semiconductor alloy layer, an electric field and an optical absorption inside the undoped semiconductor alloy quantum well layer are changed, thereby modulating field intensity passing through said undoped semiconductor alloy quantum well layer.
26. The communication link according to claim 25, wherein the electrical contact comprises at least one selected from the group of: an Indium Tin Oxide (ITO) material, a CNT material, and metamaterials including arrays of CNTs.