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.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.