Abstract

Coplanar waveguides and asymmetric coplanar strip lines¹ are used in lithium niobate couplers and interferometers to provide the electrical rf modulation signal. In general, the spacings between the lines of these structures are small, typically between 3 and 30μm and to reduce conductor loss, they are plated up to 3μm and thicker.² In these cases, the strip thickness to conductor spacing ratio becomes large (0.1 upwards), and impedance and loss calculations using the thin-strip approximation are no longer acceptable. The present paper discusses a Green’s function approach to the calculations of these parameters taking into account the strip thickness.

© 1990 Optical Society of America