1. A device removingre-inserting structure for a construction machine configured such that an upper member is mounted above a lower member as a load support member by a plurality of pillars in a state that a device installation space is formed between the lower and upper members, and that a device is horizontally removedre-inserted in the device installation space from the outside through an insertionremoval port formed in a lateral portion of the device installation space, the structure comprising:
the demountable pillar, of the plurality of pillars, which is disposed on a removalre-insertion path of the device in a state that the demountable pillar obstructs a removalre-insertion of the device, wherein
the demountable pillar is demountably mounted to the lower and upper members in such a manner as to allow a removalre-insertion of the device through the insertionremoval port.
2. The device removingre-inserting structure as defined in claim 1, further comprising:
a switching unit which switches the demountable pillar between a load support state where a total height dimension of the demountable pillar including other members is equal to the interval between the lower and upper members to support a load, and a no-load state where the total height dimension is smaller than the interval by demounting the other members, wherein
the demountable pillar is demounted from between the lower and upper members in the no-load state to allow the removalre-insertion of the device.
3. The device removingre-inserting structure as defined in claim 2, wherein
the other members include a spacer,
the switching unit is provided with a screw unit which is adapted to raise or lower a member on an upper side of the spacer by a screw thrust force of the screw unit, and
a spacer detachmentre-attachment gap is formed by the screw unit to detachre-attach the spacer, and the spacer is detached to form a pillar demountingre-mounting gap between the upper member and the lower member so as to bring the demountable pillar to the no-load state for demountingre-mounting the demountable pillar.
4. A device removingre-inserting method for a construction machine configured such that an upper member is mounted above a lower member as a load support member by a plurality of pillars in a state that a device installation space is formed between the lower and upper members, and that a device is horizontally removedre-inserted in the device installation space from the outside through an insertionremoval port formed in a lateral portion of the device installation space, the method comprising the steps of:
a first step of demountably mounting the demountable pillar, of the plurality of pillars, which is disposed on a removalre-insertion path of the device in a state that the demountable pillar obstructs a removalre-insertion of the device;
a second step of demounting the demountable pillar from between the lower and upper members; and
a third step of removingre-inserting the device in the device installation space in a state that an upper load including the upper member is supported by the other pillars.
5. The device removingre-inserting method as defined in claim 4, wherein
the demountable pillar is configured to be switchable between a load support state where a total height dimension of the demountable pillar including other members is equal to an interval between the lower and upper members to support a load, and a no-load state where the total height dimension is smaller than the interval by demounting the other members, and
the demountable pillar is demounted from between the lower and upper members in the no-load state, and is re-mounted after the removalre-insertion of the device.
6. The device removingre-inserting method as defined in claim 5, wherein
the construction machine is provided with a spacer which increases the total height dimension of the demountable pillar to bring the demountable pillar to the load support state, and a screw unit which is adapted to raise or lower a member on an upper side of the spacer by a screw thrust force of the screw unit, and
in the second step, a spacer detachmentre-attachment gap is formed by the screw unit to detachre-attach the spacer, and the spacer is detached to form a pillar demountingre-mounting gap between the upper member and the lower member so as to bring the demountable pillar (16) to the no-load state for demountingre-mounting the demountable pillar.
7. The device removingre-inserting method as defined in claim 5, wherein
the construction machine is provided with a spacer which is disposed between the upper member and the lower member, and has a predetermined thickness on an upper side or a lower side of the demountable pillar, and a screw unit which raises a member on an upper side of the spacer by a screw thrust force of the screw unit, and
the second step includes
a sub step of raising the member on the upper side of the spacer until a spacer detachmentre-attachment gap is formed by the screw unit,
a sub step of detaching the spacer upon formation of the spacer detachmentre-attachment gap,
a sub step of releasing a raised state of the upper member by the screw unit to bring the demountable pillar to the no-load state, and
a sub step of demountingre-mounting the demountable pillar fromin between the upper member and the lower member.
8. The device removingre-inserting method as defined in claim 4, wherein
a fuel tank as the device is formed with a vertically extending recess groove in a lateral portion thereof toward the insertionremoval port, and
the demountable pillar is demountably mounted to the lower and upper members in a state that the demountable pillar is received in the recess groove.
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 photonic crystal defect structure for a vertical cavity surface emitting laser:
a plurality of holes arranged in a pattern; and
at least one missing hole defect in the pattern, a ratio of the hole diameter divided by the hole pitch being dependent upon the hole depth and set to produce single transverse mode operation.
2. The structure of claim 1, wherein a radius of said missing hole defect is set to achieve single mode operation.
3. The structure of claim 1, formed as part of a vertical cavity surface emitting laser, the laser including:
a substrate;
a bottom distributed Bragg reflector;
a top distributed Bragg reflector;
an electrical current aperture;
top and bottom electrodes; and
a vertical cavity between said bottom and said top distributed Bragg reflectors containing an active region.
4. The structure of claim 3, wherein said plurality of holes and said defect are finite depth holes formed in said top distributed Bragg reflector.
5. The structure of claim 3, wherein said plurality of holes and are finite depth holes that extend through said vertical cavity and extend through at least a part of each of said top and bottom distributed Bragg reflectors.
6. The structure of claim 3, wherein said plurality of holes and are infinite depth holes.
7. The structure of claim 3, comprising a plurality of defects arranged in said pattern.
8. The structure of claim 7, wherein said pattern comprises a seven point defect pattern.
9. The structure of claim 8, further comprises additional seven point defect patterns.
10. The structure of claim 3, comprising a plurality of said patterns, wherein some of said patterns are different and some are matched to provide transverse optical coupling.
11. The structure of claim 10, wherein patterns are matched by having matched dimensions of said holes, pitch between holes, hole depth and defect radius.
12. The structure of claim 3, wherein said electrical current aperture comprises an oxidized region in said vertical cavity.
13. The structure of claim 3, wherein said electrical current aperture comprises an ion implanted region in said vertical cavity.
14. The structure of claim 3, wherein a refractive index difference within said vertical cavity is small enough to achieve single transverse mode operation.
15. The laser of claim 3, wherein a radius of said missing hole defect is set to achieve single mode operation.
16. The laser of claim 15, wherein dimensions are set such that the V-parameter of the laser is set such that Veff is less than 2.405, wherein Veff is defined by:
3
V
eff
=
2
r
n
eff
2
–
(
n
eff
–
n
)
2
where is an operating wavelength, r is an equivalent defect radius, neff is the effective refractive index of the said vertical cavity without a photonic crystal hole pattern and defect structure present, n is the refractive index reduction introduced by the said pattern and said one or more defects, and is the depth dependence single transverse mode factor.
17. The laser of claim 16, wherein n is set through optimization to an increased amount that maintains Veff is less than 2.405.
18 The laser of claim 17, wherein n is set to be greater than 103.
19. The structure of claim 1, comprising a plurality of defects arranged in said pattern.
20. A photonic crystal defect structure in a vertical cavity surface emitting laser, comprising:
a substrate;
a bottom electrode electrically contacting said substrate;
a bottom distributed Bragg reflector formed on an opposite side of said substrate from said bottom electrode;
a top distributed Bragg reflector;
a plurality of finite depth holes arranged in a pattern and a missing hole defect in the pattern, the pattern being formed in at least a portion of said top distributed Bragg reflector, the diameter, pitch and depth of the holes being defined by a depth dependence single transverse mode factor;
a vertical cavity including claddings that clad an active region, said vertical cavity being between said top and bottom distributed Bragg reflectors; and
a top electrode including an aperture larger than the pattern.
21. The structure of claim 20, comprising a plurality of defects arranged in said pattern.
22. The structure of claim 20, comprising a plurality of said patterns, wherein some of said patterns are different and some are matched to provide transverse optical coupling.