Samuel D. Conzone

Hybrid glass substrates for waveguide device manufacture

Hybrid glass substrates were prepared by a novel, low-temperature process joining active (Er-Yb codoped) and passive phosphate glass. The resulting hybrid substrates are chemically and physically robust; they can be cut, ground, and polished by conventional, water-based techniques. The entire substrate can be immersed in a molten-salt bath to produce waveguides simultaneously in the active and passive regions. A low reflectance of -34+/-2 dB was measured at the joint interface with 1531.2-nm light by optical low-coherence reflectometry. Further, a hybrid laser waveguide device exhibited a slope efficiency of 33% at 1540 nm when pumped at 975 nm.

Hybrid glass structures for telecommunication applications

Hybrid glass parts composed of dissimilar glass sections are an attractive route to integrate multiple functions onto a single substrate and offer the potential to fabricate advanced laser sources, amplifiers, lossless splitters and other photonic devices such as Fabry-Perot etalons. We review the most promising bonding technologies, placing particular emphasis on techniques that do not require the use of high processing temperatures. In particular, we discuss in detail a recently developed low temperature bonding technology that relies on inorganic adhesives. Characterization of interfacial joints prepared with this inorganic technology indicate low insertion loss, high mechanical strength and chemical resistance to attack during the conventional lithographic and ion exchange steps employed to fabricate waveguide structures.

Single-frequency and mode-locked Er/Yb co-doped waveguide lasers

Rare-earth-doped waveguide lasers have seen a significant increase in commercial and research interest over the last decade both in single-frequency and pulsed laser designs. This is due primarily to the higher doping concentrations of active ions in rare-earth-doped bulk glasses relative to rare-earth-doped fiber devices. Higher dopant concentrations allow for laser operation at decreased cavity length, which improves mode stability. We present results using Er,Yb co-doped waveguides in cw narrow-linewidth and mode-locked lasers.

Passive and active characterization of hybrid glass substrates for telecommunication applications

Phosphate glasses have become increasingly popular for planar waveguide devices owing in part to the development of a number of different commercial compositions with a wide range of optical, physical, chemical and laser properties. In addition, the recent development of low temperature bonding technology has made possible the fabrication of structures involving multiple glasses prepared as a single hybrid substrate. Combined, these new materials and technologies make possible the creation of devices with increasing integration and complexity. Here, we present passive characterization data collected on glass joints prepared with the low temperature bonding technology and active performance data of a hybrid DBR laser where the surface relief grating has been fabricated in the passive glass region of a hybrid substrate.