摘要 |
<p>An optical interference filter having high transmissivity at first and second passbands. The interference filter comprises a first stack having a plurality of dielectric layers, a second stack having a plurality of dielectric layers, and a spacer interposed between the first and second stacks. Each of the dielectric layers included in the first and second stacks have optical thicknesses which vary quadratically. The dielectric layers have alternating high and low refractive indices.</p> |