Heterostructure GaAs-Al_xGa_1-xAs-GaAs waveguides for 10.6 µm wavelength grown by liquid-phase epitaxy have a linear variation of dielectric constant in their substrates. On the basis of their mode equation, a computer program was devised for obtaining optimum values of the six parameters that define the index profiles, given a sufficient number and distribution of mode-angle measurements. The optimized parameters agreed well with the measured values for a variety of waveguides, illustrating the generality of the parameter-optimization procedure. Two types of leaky modes were observed, whose effective index β/k is less than the seed index, (1) Lummer—Gehrcke modes that are incompletely reflected at the substrate-seed interface and (2) low-loss totally reflected modes whose evanescent fields radiate into high-index seeds.

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription