A.E. Bond

Low insertion loss and low dispersion penalty InGaAsP quantum-well high-speed electroabsorption modulator for 40-Gb/s very-short-reach, long-reach, and long-haul applications

We present a metal-organic-chemical-vapor-deposition-grown low-optical-insertion-loss InGaAsP/InP multiple-quantum-well electroabsorption modulator (EAM), suitable for both nonreturn-to-zero (NRZ) and return-to-zero (RZ) applications. The EAM exhibits a dynamic (RF) extinction ratio of 11.5 dB at 1550 nm for 3 Vp-p drive under 40-Gb/s modulation. The optical insertion loss of the modulator in the on-state is -5.2 dB at 1550 nm. In addition, the EAM also exhibits a 3-dB small-signal response (S21) of greater than 38 GHz, allowing it to be used in both 40-Gb/s NRZ and 10-Gb/s RZ applications. The dispersion penalty at 40 Gb/s is measured to be 1.2 dB over /spl plusmn/40 ps/nm of chromatic dispersion. Finally, we demonstrate 40-Gb/s transmission performance over 85 km and 700 km.

Novel fabrication process for vertical resonant coupler with precise coupling efficiency control

Semiconductor /spl mu/-cavities are attractive elements to incorporate into WDM optical networks as wavelength selective elements: narrow band filters, splitters, switches and so on. To achieve narrow linewidths suitable for WDM applications, a high Q-cavity with weak and precisely controlled input and output coupling is required. To realize a free spectral range of 30-50 nm, the ring or disk cavity diameter must be decreased to the range 5-10 /spl mu/m and the cavity lateral index step must be large enough to support strongly guided ring or whispering gallery modes. In previous work these constraints were met by using evanescent coupling between waveguides and 5-20 /spl mu/m diameter resonators formed with an air/semiconductor interfaces. For single mode operation such structures require waveguides with widths on the order of 1 /spl mu/m and coupling separations /spl sim/0.1 /spl mu/m. It is difficult to control the coupling in such structures even with electron beam lithography. The approach presented in this paper exploits the ability to produce precisely controlled coupling separations through epitaxial growth rather than lithography by using a vertical coupling rather than lateral coupling structures. Our implementation of this approach enables a generic methodology for complex three dimensional waveguide structures.

Challenges in optoelectronic component packaging for next generation pluggable modules

A review of trends in optoelectronic packaging at the component and module level is presented. The trends towards smaller form factor, and lower power dissipation is discussed and the results of a cooled micro TOSA is described. The importance of micro cooler technology and micro optics to the overall technical solution is discussed, along with the application of this technology to higher functionality transmitters

Photonics integrations enabling high-end applications of InP in optical data transmissions

We present here results from a uniquely designed InP modulator chip combined with advanced packaging concepts, which enables high-end applications in optical data communications. An electroabsorption (EA) modulator, with a strained InGaAsP or InGaAlAs multiple quantum well structure, is monolithically integrated with a semiconductor optical amplifier. This design offers broad wavelength tunability while maintaining high extinction ratio, high optical output power, and high dispersion tolerance. The amplified EA modulator chip is co-packaged with a distributed feed back (DFB) laser ensuring separate optimization of the laser and modulator sections. The optical isolator, placed between the laser and modulator, completely eliminates adiabatic chirp. This Telcordia-qualified laser integrated modulator platform enables superior performance previously not thought possible for InP absorption based modulators. 11dB of dynamic extinction ratio, 5dBm of modulated output power, and ±1200ps/nm or +1600ps/nm dispersion tolerance can be simultaneously achieved in un-amplified 10Gb/s data transmission. Full C-band tunability using a single device is also demonstrated with the LIM module. Extensive simulations and transmission system evaluations shows that with the controllable chirp, the cost-effective LIM performs as well as a Mach-Zehnder modulator in dispersion managed and amplified long-haul WDM systems. Lastly, the first uncooled 10Gb/s long-reach operation at 1550nm was demonstrated with LIM packages. Using a simple control algorithm, a constant modulated output power of 1dBm with less than 1dB dispersion penalty over 1600ps/nm single mode fiber is achieved in an 80 degrees environmental temperature range without any module temperature control. Utilizing the Al-based material system, also allows a reduced variation of the extinction ratio.

850 nm VCSEL's with buried Al/sub x/O/sub y/ current apertures

Vertical cavity surface emitting lasers (VCSELs) with 850 nm emission wavelength are of great interest for short haul optical interconnections because of the compatibility with standard Si or GaAs based receivers. Low current and high wall plug efficiency VCSELs are needed. In this presentation, 850nm GaAs-AlGaAs DBR QW VCSELs using buried Al/sub x/O/sub y/ current apertures with low threshold current and peak optical output of 1.2 mW are reported.