The VDL-002 is a miniaturized variable optical delay line designed specifically for OEM applications. With a delay range of up to 250 ps, this device is a superior replacement for the variable RF phase shifters inadequately adapted from the RF/ wireless field for fiber optic communications. It is especially useful in coherent detection systems for adjusting phase or delay differences between signals. The VDL-002 eliminates the VSWR problems of RF phase shifters for high frequency and broadband signals, especially at 40 and 100Gbps. A single device can be used for any data rate, simplifying inventory management. With a footprint of only 0.72” x 1.46” x 2.2” for a delay range of 100 ps, the device can be conveniently integrated into network modules, test instruments, and OCT equipment for precision optical path length control or timing alignment. An internal mirror can be installed to cause light to double pass the device, doubling the delay range. The patent-pending design makes hermetically sealed packaging possible and enables Telcordia qualification when required. Finally, a locking mechanism is provided for locking the delay at a permanent position. The VDL-002 generally comes with single mode or PM fiber pigtails per customer requirement.