Long Wavelength Single-Mode Fibre Optic TX and RX Modules “Sugar Cubes”

The PLD-1315 and PLD-23XX Series manufactured by PD-LD are a transmitter-receiver in a “sugar cube” form-factor. The series is an ideal cost-effective fibre-optic communication solution for 150 Mb/s over short and long-range. The sugar cube form-factor allows designers to offer single-mode fibre performance in applications which currently use short wavelength (850 nm) components in identical form-factor packages. A link upgrade from multi-mode to single-mode fibre can be achieved by simply replacing the optical components on the circuit board.
    
The PLD-1315 transmitter consists of a 1300 nm Edge Emitting LED (ELED).  Such ELEDs efficiently couple their optical output into single-mode optical fibre. The drive circuit for the ELED can be the same circuitry that is used with multi-mode LED based components, versus LASER based emitters which require optical feedback.

The PLD-23XX receiver consists of a 75µm diameter InGaAs PIN photodiode and a trans-impedance amplifier (TIA) with the option of with or without Automatic Gain Control (AGC). The PIN photodiode is optimised for high response in the 1300 nm wavelength region and is matched with a low-noise TIA. The optical signals are detected by the PIN and converted to an analogue voltage output with a very low input noise current contribution.

The Automatic Gain Control feature decreases the light to voltage conversion factor when the average incident optical power is relatively high. The receiver has a sensitivity of –36 dBm at 100 MHz and, with filtering, a minimum overload value of 0dBm. This dynamic range makes the pair ideal for both short and long-range applications. A number of pin-outs are available to match other components on the market.