| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pulse time diffuser capable of generating a string of chip pulses each having a constant strength. SOLUTION: The reflection powers R<SB>1</SB>, R<SB>2</SB>and R<SB>k</SB>of a first, second and k-th (k is an integer meeting a condition 3≤k≤J) unit FBGs are given in the following formula. (a) R<SB>1</SB>=P<SB>c</SB>(constant), (b) R<SB>2</SB>=P<SB>c</SB>/(1-R<SB>1</SB>)<SP>2</SP>, (c-1)R<SB>k</SB>=(P<SB>c</SB><SP>1/2</SP>-P<SB>k</SB><SP>1/2</SP>)/ä(1-R<SB>1</SB>)<SP>2</SP>×(1-R<SB>2</SB>)<SP>2</SP>×to×(1-R<SB>k-1</SB>)<SP>2</SP>}, (c-2)R<SB>k</SB>=(P<SB>c</SB><SP>1/2</SP>+P<SB>k</SB><SP>1/2</SP>)/ä(1-R<SB>1</SB>)<SP>2</SP>×(1-R<SB>2</SB>)<SP>2</SP>×to×(1-R<SB>k-1</SB>)<SP>2</SP>}, where P<SB>c</SB>is an arbitrary constant and P<SB>k</SB>is a strength of the k-th output chip pulse to be reflected three times. In addition, expressions (c-1) and (c-2) represent the reflection powers of k-th unit diffraction gratings which have 0 andπrespectively as a phase difference between the k-th output chip pulse to be reflected once and the k-th output chip pulse to be reflected three times. COPYRIGHT: (C)2008,JPO&INPIT |
