What is claimed is:
1. A thermal insulation box provided with a front panel removably attached to a front part of a casing body having a forward opening; the front panel comprising a panel body for covering the forward opening of the casing body, the panel body being blow-molded by a synthetic resin integrally with a front frame member for regulating inward dislocation of a right sidewall and a left sidewall of the casing body defining the forward opening; the panel body and the front frame member containing a foamed heat-insulating material in their hollow spaces.
2. The thermal insulation box according to claim 1, further comprising a top plate covering an upward opening of the casing body, wherein the front panel and the top plate have an engaging portion and a counterpart engaging portion, respectively, which are engageable with each other; the front panel being attached to and detached from the casing body by engagement and disengagement of the engaging portion with respect to the counterpart disengaging portion of the top plate covering the upward opening.
3. The thermal insulation box according to claim 1 or 2, wherein the top plate covering the upward opening of the casing body is a blow-molded by a synthetic resin and contains in its hollow space a foamed heat-insulating material obtained by foam molding.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. An optical switch comprising:
a first trench adapted to hold index-matching fluid;
a second trench adapted to hold the index-matching fluid, said second trench connected to said first trench;
a first expansion chamber connected to said first trench; and
a second expansion chamber connected to said second trench.
2. The optical switch recited in claim 1 wherein said first expansion chamber is adapted to hold gas.
3. The optical switch recited in claim 2 wherein said inert gas is nitrogen.
4. The optical switch recited in claim 1 further comprising a first heater proximal said first expansion chamber, said first heater adapted to heat said first expansion chamber.
5. The optical switch recited in claim 4 further comprising a second heater proximal to said second expansion chamber, said second heater adapted to heat said second expansion chamber.
6. The optical switch recited in claim 1 wherein an aperture connects said first trench with said second trench.
7. The optical switch recited in claim 6 wherein said aperture has a height ranging from 7 microns to 20 microns.
8. An optical switch array comprising a plurality of optical switches, each optical switch comprising:
a first trench adapted to hold index-matching fluid;
a second trench adapted to hold the index-matching fluid, said second trench connected to said first trench;
a first expansion chamber connected to said first trench, said first expansion chamber adapted to hold gas; and
a second expansion chamber connected to said second trench, said second expansion chamber adapted to hold gas.
9. The optical switch array recited in claim 8 further comprising a first heater adapted to heat the gas in said first expansion chamber.
10. The optical switch array recited in claim 9 further comprising a second heater adapted to heat the gas in said second expansion chamber.
11. The optical switch array recited in claim 8 wherein the index-matching fluid is non-wetting on surfaces of said first trench and said second trench.
12. A method for switching optical signals from an input waveguide terminating at a first trench to an output waveguide also terminating at the first trench, the method comprising shifting index-matching fluid from the first trench connected to a first expansion chamber to a second trench by causing gas within said first expansion chamber to expand whereby the expanding gas pushes the index-matching fluid from said first trench to said second trench and thus changing optical properties of said first trench.
13. The method recited in claim 12 further comprising heating the first expansion chamber causing the gas within the first expansion chamber to expand.
14. The method recited in claim 12 further comprising heating a second expansion chamber, connected to the second trench, thereby causing gas within the second expansion chamber to expand, pushing the index-matching fluid from the second trench chamber to the first trench.
15. The method recited in claim 12 wherein the first expansion chamber is adapted to hold inert gas.
16. The method recited in claim 15 wherein said inert gas is nitrogen.
17. The method recited in claim 12 wherein an aperture connects the first trench with the second trench.
18. The optical switch recited in claim 17 wherein the aperture has a height ranging from 7 microns to 20 microns.