| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a thermo-optic type light attenuator which is resistant to an ambient temperature change and which can be controlled only by an electric current. SOLUTION: A Mach-Zehnder circuit C, which branches and recombines inputted light is formed on a quartz substrate 2 for configuring an optical circuit. The thermo-optic type light attenuator 1 adjusts and outputs the light inputted by the energization of heaters formed on the Mach-Zehnder circuit C. The heaters are constituted by electrically connecting in series first heaters 8a and 8b and second heaters 9a and 9b, in which the signs of the temperature coefficient of a resistance value are different with each other, and the resistance value is equal with each other at a certain temperature.</p> |
