Traveling-wave Laser Amplifier Research Articles

5.2 dB noise figure in a 1.5 μm InGaAsP travelling-wave laser amplifier

The letter presents a theoretical and experimental study of the noise characteristics of a 1.5 μm InGaAsP travelling-wave laser amplifier. The noise figure representing the signal-spontaneous beat noise level measures 5.2 dB, which is the smallest value thus far reported. The spontaneous spontaneous beat noise increases with the square of the signal gain.

Signal gain saturation in two-channel common amplification using a 1.5μm InGaAsP travelling-wave laser amplifier

Signal gain saturation and crosstalk characteristics in two-channel common amplification were investigated using a 1.5μm travelling-wave laser amplifier. Simultaneous amplification in the two channels causes gain saturation of the other, which results in an approximate 3 dB reduction in saturation output power. The total output power is confirmed to dominate the gain saturation in laser amplifiers.

Fabrication and performance of 1.5μm GaInAsP travelling-wave laser amplifiers with angled facets

A broadband 1.5μm GaInAsP travelling-wave laser ampli-fier has been realised with angled facets instead of anti-reflection coatings. The measured signal gain for the TE mode is 19dB at the wavelength around 1.49μm with a 2dB gain ripple over one free spectral range and a 3dB band-width of 55 nm. The estimated residual modal reflectivity is 0.2%.

Wideband 1.5μm optical receiver using travelling-wave laser amplifier

A high-sensitivity, wideband optical receiver using a travelling-wave laser amplifier in conjunction with a PIN photodiode and commercial 50Ω amplifier is described. A sensitivity of -37 dBm at 1 Gbit/s has been achieved, with a 17dB net amplifier gain.

Injection traveling-wave laser amplifier based on a (GaAI)As double heterostructure

Theoretical and experimental investigations were made of single-pass amplification of narrow-band optical signals in resonator-free stripe heterostructures operated at room temperature. The following optophysical characteristics of laser amplifiers of this type were recorded: the maximum gain was 26 dB; the output signal/background ratio was up to 7 dB without spectral selection and up to 24 dB when an output filter with a pass band 0.1 nm wide was used; the sensitivity was of the order of 100 nW; the output signal power was up to 20 mW; the linear operation range was in excess of 20 dB; the response time in the linear region was less than 1 nsec. The experimental results were in satisfactory agreement with calculations.

Proposals and analyses on laser amplifier based integrated optical circuits

Simplified traveling wave laser (TWL) amplifier equations are given based on a lumped model. Pulse transfer characteristics for a TWL amplifier are examined theoretically. A new class of integrated optical amplifier with three terminals (OPATT) has been proposed as an optical analog of the electric transistor. Analytical formulas and dynamic properties of an OPATT have been considered. OPATT-based optical integrated circuits, including optical differential amplifiers, comparators, saturable oscillators, and optical logic gates, have been investigated theoretically.

Stimulated Raman scattering from a multigigawatt liquid laser amplifier

Stimulated Raman scattering has been observed for the first time during the amplification of giant pulses in a travelling-wave laser amplifier using Nd+3 : POCl3 : ZrCl4 as the active medium. Spectral and time characteristics of the input and output pulses are reported as well as measurements of the energy conversion to Raman wavelengths. The generation of forward-travelling narrow intense light pulses due to stimulated Raman scattering is also reported.

Intensity stabilization of dye laser radiation by saturated amplification

A novel scheme is proposed for stabilizing the intensity of a fluctuating laser source, using a partly saturated high gain traveling wave laser amplifier with a nonsaturable absorber distributed in the amplifying medium. Calculations for homogeneously broadened laser gain band in an adiabatic approximation are presented, which indicate that the stabilization factor can be increased by several orders of magnitude with the help of the absorber. An experiment is reported in which a two-stage dye laser amplifier with inserted attenuator, pumped by a nitrogen laser, is used to amplify and stabilize the intensity of an ultra-narrowband repetitively pulsed dye laser. The output intensity changes by less than a factor of four when the input is changed over three orders of magnitude.

Sensitivity of a neodymium-glass laser amplifier

The results of an experimental study of the sensitivity of a neodymium-glass laser amplifier are presented. The sensitivity of a traveling wave laser amplifier is shown to be close to the theoretical limit, being 1.7 · 10−6 W for a pass band of 6 · 1012 cps.