Kaiam uses Ensphere’s 10G shunt laser driver for 40G quad transmit subassembly

Optical component startup Kaiam Corp. is using the ESI-1010 10G shunt laser driver from Ensphere Solutions in Kaiam’s new 40-Gbps compact QSFP+ transmit optical subassembly (TOSA), Ensphere reports.

Kaiam uses what it calls “silicon micromechanics” to create photonic integrated circuits (PICs) that are the basis of its products (see “Kaiam debuts with 40-Gbps LR4 transmitter, receiver optical subassemblies”) Its first products are targeted at emerging high-speed QSFP+ optical transceiver modules.

Ensphere has engineered its ESI-1010 laser driver to fit into TOSA packages such as those Kaiam envisions (see “Ensphere Solutions debuts 10-Gbps transceiver and laser diode shunt driver ICs”). The ESI-1010 single-channel 10G laser diode driver is designed to support a wide variety of laser RC time constants. It supplies up to 100 mA of bias and 50 mA of modulation currents.

In a shunt configuration, the ESI-1010 assumes the burden of driving a low impedance laser diode while presenting a 50Ω load to the preceding driver, which is far easier to drive. Using a shunt configuration significantly reduces overall power requirements, Ensphere asserts.

“The next generation 40-Gbps pluggable modules (QSFP+) for singlemode fiber require more than an order of magnitude reduction in area. ESI-1010 has been a key element, allowing us to increase the density while simultaneously reducing power dissipation and improving signal integrity,” said Dr. Thomas Schrans, Kaiam’s vice president of engineering and product development.

Complementing its work with Ensphere, Kaiam also has partnered with Opnext for the supply of 1310-nm uncooled lasers.

September 30, 2011

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