Berton Callicoatt

Passively mode-locked glass waveguide laser with 14-fs timing jitter

Ultralow jitter pulse trains are produced from a passively mode-locked, erbium/ytterbium co-doped, planar waveguide laser by use of high-bandwidth feedback control acting on the physical cavity length and optical pump power. Synchronization of a 750-MHz, fundamentally mode-locked laser to an external clock signal yields an ultralow, root-mean-square relative timing jitter of 14.4 fs integrated from 10 Hz to the Nyquist frequency of 375 MHz.

Passively mode-locked waveguide laser with low residual jitter

Picosecond pulses at 1.53 /spl mu/m with low residual jitter are generated from a passively mode-locked erbium/ytterbium codoped planar waveguide laser in an extended cavity configuration. The round-trip frequency of the laser cavity is actively referenced to the frequency of a stable electronic oscillator; this lowers the residual root-mean-square timing jitter to 83 fs over the frequency range of our phase-noise measurement system 100 Hz-10 MHz.

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.

Compact solid-state waveguide lasers

Glass waveguide lasers will fill an important niche as optical sources in communication, RF photonics, and optical metrology. This is primarily because waveguide lasers benefit from compact size, low noise, relatively high output powers, long upper-state lifetimes, and simple integration with optical-fiber-based systems. Although we do not expect waveguide lasers and amplifiers to ever supplant fiber and semiconductor lasers and amplifiers in every possible communications application, waveguide lasers have a number of advantages over traditional lasers for these uses. Single-frequency waveguide lasers provide narrow linewidth and high output power in a compact, monolithic package. The narrow linewidth is an important advantage over standard semiconductor lasers, and the compact size makes single-frequency waveguide lasers better suited than fiber lasers or extended-cavity semiconductor lasers for many applications.

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.