2.7.3 Fiber Lasers
Application in OEO of low-noise fiber lasers (FL) is promising. The fiber lasers with
activated erbium (Er) or ytterbium (Y) dopes (the wavelength is 1.55 μm) with the
ultralow phase noise of the fiber laser optical emission [42–44] are commercially
available. The construction of fiber lasers consists of the closed ring of the optical
activated fiber, to which the optical pumping emission is applied with the help of the
Fig. 2.10 (a) Experimental results of phase noise measurement of QWLD emission with the
discriminator on the base of high-Q diffraction grating, which is used for reduction of the QWLD
phase noise, and (b) the calculated function (based on QWLD phase noise measurement, see (a)) of
the relative emission power vs. the offset from central frequency of the QWLD spectrum without
and with a discriminator. Curve 1—QWLD without discriminator. Curve 2—QWLD with use of
the high-Q resonator on the base of the high-Q diffraction grating. The analysis time is 1 ms (b)
2.7 Modern Elements of OEO: A Laser, the Optical Fiber, and a Photodetector
43
Application in OEO of low-noise fiber lasers (FL) is promising. The fiber lasers with
activated erbium (Er) or ytterbium (Y) dopes (the wavelength is 1.55 μm) with the
ultralow phase noise of the fiber laser optical emission [42–44] are commercially
available. The construction of fiber lasers consists of the closed ring of the optical
activated fiber, to which the optical pumping emission is applied with the help of the
Fig. 2.10 (a) Experimental results of phase noise measurement of QWLD emission with the
discriminator on the base of high-Q diffraction grating, which is used for reduction of the QWLD
phase noise, and (b) the calculated function (based on QWLD phase noise measurement, see (a)) of
the relative emission power vs. the offset from central frequency of the QWLD spectrum without
and with a discriminator. Curve 1—QWLD without discriminator. Curve 2—QWLD with use of
the high-Q resonator on the base of the high-Q diffraction grating. The analysis time is 1 ms (b)
2.7 Modern Elements of OEO: A Laser, the Optical Fiber, and a Photodetector
43