| US 7,512,344 B2 | ||
| Variable dispersion compensator | ||
| Toshiki Sugawara, Kokubunji (Japan); and Satoshi Makio, Kumagaya (Japan) | ||
| Assigned to Hitachi Metals Ltd., Tokyo (Japan) | ||
| Filed on Jul. 11, 2005, as Appl. No. 11/177,327. | ||
| Claims priority of application No. 2004-207049 (JP), filed on Jul. 14, 2004; application No. 2005-036299 (JP), filed on Feb. 14, 2005; and application No. 2005-037623 (JP), filed on Feb. 15, 2005. | ||
| Prior Publication US 2006/0013529 A1, Jan. 19, 2006 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. H04B 10/12 (2006.01) | ||
| U.S. Cl. 398—147 [398/148; 398/149; 398/158; 398/159; 398/81; 385/27; 385/31; 385/129; 385/147] | 9 Claims |
| 1. A variable dispersion compensator, comprising:
a plus-side variable dispersion compensating unit having, in a relational expression representing a dispersion relative to
wavelength, a positive gradient “a1” and an effective band W1 of the gradient “a1”;
a minus-side variable dispersion compensating unit having, in the relational expression representing the dispersion relative
to wavelength, a negative gradient “a2” and an effective band W2 of the gradient “a2”;
first temperature-adjusting means that shifts dispersion characteristics of said plus-side variable dispersion compensating
unit, in a wavelength direction; and
second temperature-adjusting means that shifts dispersion characteristics of said minus-side variable dispersion compensating
unit, in a wavelength direction inverse to that of said plus-side variable dispersion compensating unit;
wherein the gradients “a1” and “a2” have signs opposite to each other and have the same absolute quantity or equal to or smaller than 0.1 in differential relative
quantity |(a1−a2)/a1| between the gradients.
|