The VDL-004 is a miniature variable optical delay line designed specifically for OEM applications. This device offers continuous control with high precision, zero backlash, and good thermal stability. An internal mirror can be installed to cause light to double pass the device, doubling the delay range. A locking mechanism is provided for locking the delay at a permanent position. The VDL-004 generally comes with single mode or PM fiber pigtails per customer requirement. With a footprint of only 78x22x15 mm for a delay range of 130 ps (40 mm), the device can be easily integrated into larger instruments or assemblies for precision optical path length control or timing alignment. Convenient mounting brackets allow mounting in any orientation, as well as easy integration of multiple units on a base plate to form an array.