Abstract:
Laser source including materials with negative index of refraction dependence on temperature and with temperature independent coincidence between cavity modes and a set of specified frequencies such as DWDM channels in telecommunications applications. The free spectral range may be adjusted to equal a rational fraction of the specified frequency interval. The operating frequency may be defined by a frequency selective feedback element that is thermo-optically tuned by the application of heat from an actuator without substantially tuning the cavity modes. The operating frequency may be induced to hop digitally between the specified frequencies. In a particular embodiment, semiconductor amplifier and polymer waveguide segments form a linear resonator with a thermo-optically tuned grating reflector. In a further embodiment, an amplifier and two waveguides from a tunable grating assisted coupler form a ring resonator. Tuning may also be accomplished by means of applying an electric field across a liquid crystal portion of the waveguide structure within the grating.
Abstract:
Laser source (100) including materials (122, 124) with negative index of refraction dependence on temperature and with temperature independent coincidence between cavity modes and a set of specified frequencies such as DWDM channels in telecommunications applications. The free spectral range may be adjusted to equal a rational fraction of the specified frequency interval. The operating frequency may be defined by a frequency selective feedback element (130, 132) that is thermo-optically tuned by the application of heat from an actuator without substantially tuning the cavity modes. The operating frequency may be induced to hop digitally between the specified frequencies. In a particular embodiment, semiconductor amplifier (110) and polymer waveguide segments (122, 124) form a linear resonator with a thermo-optically tuned grating reflector (130, 132). In further embodiments (Figs. 9 and 10), an amplifier (916, 1016) and two waveguides from a tunable grating assisted coupler (930, 1030) form a ring resonator. Tuning may also be accomplished by means of applying an electric field (1122, 1124, 1126) across a liquid crystal portion (1142) of the waveguide structure (Fig. 11B) within the grating.
Abstract:
An asymmetric waveguide pair (1440) with a differential thermal response has an optical coupling frequency that may be thermo-optically tuned. Tuning may also be accomplished by applying an electric field (1445) across a liquid crystal portion (1442) of the waveguide structure. The waveguide pair may include a grating and be used as a frequency selective coupler for an optical resonator. The differential waveguide pair may also be used as a temperature or electric field sensor, or it may be used in a waveguide array to adjust a phase relationship, e.g. in an arrayed waveguide grating.