The foundation of our capabilities is EMCORE’s world-class 7,000 square foot wafer fabrication facility at our headquarters in Alhambra, CA. It features 2” and 3” wafer processes for InP-based devices including High-Power Gain Chips and MZ Modulators, Semiconductor Optical Amplifiers (SOA), and Laser, APD & PIN Photodetector chips.
Gain Chips and Semiconductor Optical Amplifiers (SOA)
SOA provides amplification for both CW and pulsed signals and are often used in telecommunication systems operating at signal wavelengths near 1300 nm and 1550 nm. SOA gain chip can also be used for constructing external cavity lasers which have been used for high bit-rate coherent transmission and wavelength agile optical networks.
Below is simple illustration of how an optical amplifier works. An optical signal is amplified when it passes through an amplifier while the optical amplifier adds additional noises when it amplifies the signal. Usually, three key parameters define the performance of an optical amplifier:
Output power: Pout
Gain: G = Pout/Pin
Noise figure: NF = SNRin/SNRout
The biggest advantage of SOA comes from its electrical pumping, small size, and low cost. It is a competitive solution for many applications. The disadvantages of SOA are its higher noise figure and stronger nonlinearity (SPM and FWM) compared to the other amplifiers.
SOA is based on semiconductor chips that are made from compound semiconductors such as GaAs/AlGaAs, InP/AlGaAs, InP/InGaAsP and InP/InAlGaAs which are same materials used for semiconductor lasers. The difference is that lasers have a cavity formed around the gain medium to generate and maintain oscillation, the signal experiences multiple round trips inside the cavity before output. In an SOA traveling-wave amplifier used in most applications, light travels through the gain medium just one time.
The basic form of SOA is a semiconductor chip, sometimes called a gain chip. An SOA chip or gain chip is cleaved from a wafer that is made with a special fabrication process. A single wafer can produce thousands of chips.
An SOA chip can be mounted to a chip carrier, that is a so-called Chip-On-Carrier (COC). The carrier serves as a platform for electrical connection and thermal dissipation. An SOA chip can also be assembled into module packages with fiber-coupled input and output. The butterfly-type package is usually used. XMD and coaxial type packages with fiber coupling are also possible.
With the rapid growth of integrated optics, SOA has seen more applications as a basic building block used in conjunction with silicon photonic devices.
For more information on EMCORE SOA and Gain Chips read our Whitepaper.
Coherent Lasers for Data Center
Chips for coherent lasers share the same basic physical structure with SOA gain chip. The difference is the addition of optical cavity formed by HR coating on the facet(s) and/or distributed feedback grating written on the chip. EMCORE’s specially designed DFB laser provide excellent performance with mode-hop free, high output power and very narrow linewidth.
Data centers are expected to require higher data rates of 800 Gbps or even 1.6 Tbps in the future. The expectation for inter- and intra-data center applications at these high data rates includes the need for a highly coherent laser source. Higher power will be desired at about 18 dBm or more and most applications will require narrow linewidth of <200 KHz. These devices will likely be in the O-Band, however, EMCORE has the capability to support both O- or C-Band.
For more information on Coherent Lasers for Data Center read our Whitepaper.
EMCORE is ready to engage with customers on a custom design to meet your exact needs. For a consultation with your EMCORE representative on your application and requirements, Email Us or call 626-293-3400, Ext. 2.