The E2560 (without integral driver IC) and E2580 (with integral driver IC) are devices for 10 Gbits/s DWDM or TDM transmission applications, which integrate a CW laser with an electroabsorptive modulator in the same semiconductor chip, and are an extension of Lucent Technologies Microelectronics Groups' existing E2500 series of devices. Both types use a small-profile Gilbert GPO connector to handle the RF signal. The device is typically coupled with a number of erbium-doped fiber amplifiers, such as Lucent Technologies' 1724-series, in order to ensure that sufficient optical power reaches the receiver. These devices can replace external modulators which are often bulkier, more expensive, and require more complex drive electronics than the EML. Both E2560 and E2580 are available for transmission distances of 40 km and 80 km. The package also contains a thermoelectric cooler, thermistor, rear facet monitor photodiode, and an optical isolator.