Laser vibrometer

An laser vibrometer for measuring the rate at which a specified target vibrates comprised of:

• (a) means for producing a first laser beam;
• (b) a laser beam splitter disposed in front of said means for producing a first laser beam, wherein:
• 1. a portion of said first laser beam is transmitted through said laser beam splitter as a second laser beam, and
• 2. a portion of said first laser beam is reflected by said laser beam splitter as a third laser beam;
• (c) a first reflector comprised of reflective tape attached to said target disposed in the path of said second laser beam and adapted to produce a fourth laser beam reflected back to said laser beam splitter;
• (d) a second reflector disposed in the path of said third laser beam and adapted to produce a fifth laser beam reflected back to said laser beam splitter;
• (e) an optical processor comprised of a top face, wherein:
• 1. said fourth laser beam is reflected by said laser beam splitter as a sixth laser beam directed towards said top face of said optical processor, and
• 2. said fifth laser beam is transmitted by said laser beam splitter as a seventh laser beam towards said top face of said optical processor, wherein said sixth laser beam and said seventh laser beam interfere with each other to produce a laser beam interference pattern;
• 3. said optical processor is comprised of a bi-cell containing a first optical sensor and a second optical sensor separated from each other by a distance of from 0.5 millimeters to 5.0 centimeters, wherein each of said optical sensors converts said laser beam interference pattern into electrical signals, including a first electrical signal and a second electrical signal, which vary in intensity, whereby said first electrical signal and said second electrical signal are produced by said first sensor and said second sensor, respectively;
• (f) means for amplifying each of said first electrical signal and said second electrical signal, thereby producing an amplified first electrical signal and an amplified second electrical signal;
• (g) means for digitizing each of said amplified first electrical signal and said amplified second electrical signal, thereby producing a first digitized signal and a second digitized signal;
• (h) flip flop means for combining said first digitized signal and said second digitized signal into a Q signal and a Q bar signal;
• (i) means for combining said Q signal with said second digitized signal, thereby producing a first input signal;
• (j) means for combining said Q bar signal with said second digitized signal, thereby producing a second input signal;
• (k) an up counter and a down counter for counting said first input signal and said second input signal and for producing a digital sequence based upon such counting.