1. A fuel injection valve for an internal combustion engine, having a valve element, a valve seat, multiple fuel nozzle holes provided downstream from the valve seat, a spring for pressing the valve element against the valve seat side, and a valve drive actuator for moving the valve element away from the valve seat against the spring to open the valve based on a valve opening signal, wherein the nozzle holes are constituted by at least a pair of nozzle holes and configured such that, upon valve opening of the injection valve, liquid columns of fuel injected from the pair of nozzle holes collide with each other before break-up of the liquid columns,
the fuel injection valve further comprising a fuel flow control portion that controls a flow of the fuel flowing into at least one of the pair of nozzle holes so as to make swirl forces of the fuel liquid columns injected from the pair of nozzle holes differ from each other.
2. The fuel injection valve according to claim 1, wherein the pair of nozzle holes are set so as to form a liquid film by collision of the injected fuel liquid columns and break up it after liquid film formation, and
wherein regarding the swirl forces of the fuel liquid columns, the fuel flow control portion is configured to apply a swirl force to a fuel injected from one of the pair of nozzle holes while applying a smaller or little swirl force to a fuel injected from the other of the pair of nozzle holes in comparison with the one nozzle hole.
3. The fuel injection valve according to claim 1, wherein the fuel flow control portion is configured to make fuel flow velocity distributions in a circumferential direction at inlets of the pair of nozzle holes differ from each other thereby to make the swirl forces between the nozzle holes differ from each other.
4. The fuel injection valve according claim 1 further comprising a nozzle plate in which the multiple nozzle holes are provided,
wherein a top surface to be an upstream side surface of the nozzle plate is provided with a step height for making a difference in height on the top surface, and thereby the step height configures the fuel flow control portion,
wherein at least one pair of nozzle holes is provided at a lower portion to be a lower surface in the difference in height, wherein one of the pair of nozzle holes at the lower portion is placed close to a wall of the step height such that the inlet of the one of the pair of nozzle holes is subjected to control of the fuel flow with the wall of the step height.
5. The fuel injection valve according to claim 4, wherein a height H of the step height is equal to or greater than ( 110)R with respect to a radius R of the nozzle hole radius R, and
wherein a shortest distance between the step height and the pair of nozzle holes is equal to or less than 3R.
6. The fuel injection valve according to claim 1 further comprising a nozzle plate in which the multiple nozzle holes are provided,
wherein a countersunk-like hole portion larger than a diameter of the nozzle hole diameter is provided at an inlet of at least one of the pair of fuel nozzle holes in a top surface to be an upstream side surface in the nozzle plate, and
wherein a wall surface of the countersunk-like hole portion configures the fuel flow control portion by offsetting a center of the countersunk-like hole portion with respect to a center of the nozzle hole provided with the countersunk-like hole portion.
7. The fuel injection valve according to claim 6, wherein the countersunk-like hole portion has a radius equal to or less than 3R with respect to a radius R of the nozzle hole, and a depth equal to or greater than ( 110)R.
8. The fuel injection valve according to claim 6, wherein the countersunk-like hole portion is provided at both inlets of the pair of nozzle holes, and at least one of a diameter, an offset amount and a depth of the countersunk-like hole portion is different between the both nozzle holes.
9. The fuel injection valve according to claim 1, further comprising a nozzle plate in which the multiple nozzle holes are provided,
wherein a top surface to be an upstream side surface of the nozzle plate is provided with a local depression portion, and an inlet of one of the pair of nozzle hole is placed in the local hollow portion, and
wherein the local hollow portion has an asymmetric shape with respect to a line connecting between a center of the nozzle plate and the center of the one nozzle hole placed in the local hollow portion, and thereby a part of the inlet of the one nozzle hole is close to a part of an edge wall of the local hollow portion, thus, the edge wall of the local hollow portion configures the fuel flow control portion.
10. The fuel injection valve according to claim 1, further comprising a nozzle plate in which the multiple nozzle holes are provided,
wherein a top surface to be an upstream side surface of the nozzle plate is provided with a projection, and an inlet of one of the pair of nozzle holes is placed close to the projection, thus, a side wall of the projection configures the fuel flow control portion.
11. The fuel injection valve according to claim 1, wherein an end of a movable valve element of the fuel injection valve is provided with a flat face portion and a step height formed at an edge of the flat face portion, and one of the pair of the nozzle holes is placed close to a wall of the step height of the movable valve element such that a wall of the step height configures the fuel flow control portion.
12. The fuel injection valve according to claim 9, wherein a height H of the step height on the valve element side is equal to or greater than ( 110)R with respect to a radius of the nozzle hole, and wherein a shortest distance between the step height and the pair of nozzle holes is equal to or less than 3R in a minimum stroke of the valve element upon fuel injection valve drive.
13. The fuel injection valve according to claim 1, wherein the multiple nozzle holes are divided into groups to form two-directional fuel sprays, and each group is provided with the pair of nozzle holes and the fuel flow control portion.
14. A vehicle internal combustion engine having an intake port, an intake valve, an exhaust valve and a cylinder,
wherein the fuel injection valve according to claim 13 is equipped to the intake port, and set so as to travel two-directional fuel sprays injected from the fuel injection valve toward the intake valve, and
wherein the direction of the fuel injected from the pair of nozzle holes is changed by the fuel flow regulator based on at least one of change of fuel pressure and change of valve element stroke amount.
15. The fuel injection valve according to claim 2, wherein the fuel flow control portion is configured to make fuel flow velocity distributions in a circumferential direction at inlets of the pair of nozzle holes differ from each other thereby to make the swirl forces between the nozzle holes differ from each other.
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. An apparatus comprising:
an optical fiber;
a first reflector deposited on an end of the optical fiber; and
an optical cavity material deposited on a surface of a second reflector,
wherein the first reflector is configured to be placed into optical contact with a surface of the optical cavity material that is opposite to the surface on which the second reflector is deposited.
2. The apparatus of claim 1, further comprising a third reflector deposited on the surface of the optical cavity material that is opposite to the surface on which the second reflector is deposited.
3. The apparatus of claim 2, wherein the third reflector is a partial reflector.
4. The apparatus of claim 3, wherein the first reflector and the third reflector form a combined reflector when the first reflector and third reflector are in optical contact.
5. The apparatus according to claim 4, wherein spectral properties of the combined reflector match spectral properties of the second reflector.
6. The apparatus of claim 2, wherein a resonance condition is created when the first reflector and the third reflector are in optical contact.
7. The apparatus of claim 6, further comprising an alignment gap between the first and third reflector in optical contact.
8. The apparatus according to claim 1, wherein the optical fiber is a single mode optical fiber.
9. The apparatus of claim 1, wherein the first reflector, optical cavity material, and second reflector are configured to form a laser.
10. The apparatus of claim 9, wherein the laser is configured to emit light through the optical fiber.
11. The apparatus of claim 1, wherein the optical fiber has a core and a cladding, the cladding surrounding the core, and
first reflector has a first portion adjacent the core, and a second portion adjacent the cladding,
wherein the first portion has a different spectral reflectivity than that of the second portion.
12. The apparatus of claim 11, wherein the first portion is photo-oxidized, and the second portion is not photo-oxidized.
13. The apparatus according to claim 1, wherein the optical cavity material comprises a multi-quantum well heterostructure.
14. The apparatus according to claim 1, wherein each reflector comprises alternating layers of III-V compound materials.
15. The apparatus of claim 1, wherein each reflector comprises a distributed Bragg reflector.
16. The apparatus of claim 1, wherein the first reflector is deposited on the end of the optical fiber by evaporative coating, sputter deposition, integration of a monolithically fabricated mirror, or combinations thereof.
17. A laser comprising:
an optical fiber having a first reflector integrated on an end of the optical fiber, and
an integrated unit comprising:
a second reflector, and
an optical cavity material;
wherein the integrated unit and the optical fiber are in optical contact, and wherein the optical cavity material is located between the first reflector and the second reflector.
18. The laser of claim 17, wherein the first reflector covers a cladding and a core of the end of the optical fiber.
19. The laser of claim 18, wherein a first region of the first reflector adjacent to the core has a different spectral reflectivity than a second region of the first reflector adjacent to the cladding.
20. The laser of claim 19, wherein a spectral reflectivity of the first region of the first reflector is the same as a spectral reflectivity of the second reflector.
21. The laser of claim 19, wherein the cross-sectional area of the first region of the first reflector adjacent to the core is in alignment with a cross-sectional area of the core.
22. The laser of claim 17, wherein the first reflector and second reflector comprise distributed Bragg reflectors.
23. The laser according to claim 17, wherein each reflector comprises alternating layers of III-V compound materials.
24. The laser of claim 17, wherein the optical cavity material comprises a multi-quantum well heterostructure.
25. The laser of claim 17, wherein the integrated unit further comprises a third reflector, wherein the second and third reflector are deposited on opposite sides of the optical cavity material.
26. The laser of claim 25, wherein a combined spectral reflectivity of the first reflector and third reflector in optical contact is the same as a spectral reflectivity of the second reflector.
27. The laser of claim 26, further comprising an alignment gap between the first and third reflector in optical contact.
28. The laser of claim 17, wherein the laser is a vertical cavity surface emitting layer (VCSEL).
29. The laser of claim 17, wherein the laser is configured to output laser radiation through the optical fiber.
30. The laser of claim 17, wherein the laser is configured to receive a pump beam for optically pumping the optical cavity material in order to achieve lasing.
31. The laser of claim 17, further comprising electrodes configured to electrically pump the optical cavity material with an injection current in order to achieve lasing.
32. (canceled)