Generation of Arbitrary Frequency Chirps with a Fiber-Based Phase   Modulator and Self-Injection-Locked Diode Laser
  We present a novel technique for producing pulses of laser light whose frequency is arbitrarily chirped. The output from a diode laser is sent through a fiber-optical delay line containing a fiber-based electro-optical phase modulator. Upon emerging from the fiber, the phase-modulated pulse is used to injection-lock the laser and the process is repeated. Large phase modulations are realized by multiple passes through the loop while the high optical power is maintained by self-injection-locking after each pass. Arbitrary chirps are produced by driving the modulator with an arbitrary waveform generator. 
C.E. Rogers III, M.J. Wright, J.L. Carini, J.A. Pechkis, and P.L.   Gould