Abstract
We obtained a sufficiently powerful second harmonic signal, excesses 10 mW, by doubling an external-cavity diode laser that is amplified to 95 mW by an erbium-doped fiber amplifier in a periodical poled lithium niobate waveguide to lock a frequency-doubled laser source directly to the 5S/sub 1/2/ /spl rarr/ 7S/sub 1/2/ two photon transitions of rubidium. Our experimental scheme provides a compact, high-performance frequency standard in S-band (1460 nm /spl sim/1525 nm) for fiber-optic communication and sensing applications.