High energy, single frequency, tunable laser source operating in burst mode for space based lidar applications

Cosentino, Alberto; Mondello, Alessia; Sapia, A.; D’Ottavi, A.; Brotini, Mauro; Nava, Elisur Arteaga; Stucchi, Emanuele; Trespidi, Franco; Mariottini, C.; Wazen, P.; Falletto, Nicolas; Fruit, Michel

doi:10.1117/12.2308024

Cited by 4 publications

(4 citation statements)

References 4 publications

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“…A flip-flop mechanism provides the ability to switch between the two fully redundant laser transmitters, referred to as flight models A and B (FM-A, FM-B). Both lasers are realized as diode-pumped Nd:YAG lasers in a master oscillator power amplifier configuration that are frequency-tripled to 354.8 nm emission wavelength (ESA, 2008;Cosentino et al, 2012Cosentino et al, , 2017Lux et al, 2020a). A nonplanar Nd:YAG ring laser, frequency-locked to an ultra-low-expansion cavity, provides narrowband seed radiation that is fiber-coupled into the folded cavity of the 80 cm long Q-switched master oscillator (MO).…”

Section: Aladin Configuration and Measurement Principlementioning

confidence: 99%

“…A nonplanar Nd:YAG ring laser, frequency-locked to an ultra-low-expansion cavity, provides narrowband seed radiation that is fiber-coupled into the folded cavity of the 80 cm long Q-switched master oscillator (MO). The MO cavity length is actively controlled by means of a piezo actuator in order to find the optimal condition for single longitudinal mode operation for each laser pulse (Cosentino et al, 2017). The cavity control scheme is based on the ramp-hold-fire technique (Henderson et al, 1986), which involves the detection of cavity resonances of the injected seed radiation while sweeping the cavity length and firing the Q-switch at the detected resonance position of the piezo actuator.…”

Section: Aladin Configuration and Measurement Principlementioning

confidence: 99%

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ALADIN laser frequency stability and its impact on the Aeolus wind error

et al. 2021

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Abstract. The acquisition of atmospheric wind profiles on a global scale was realized by the launch of the Aeolus satellite, carrying the unique Atmospheric LAser Doppler INstrument (ALADIN), the first Doppler wind lidar in space. One major component of ALADIN is its high-power, ultraviolet (UV) laser transmitter, which is based on an injection-seeded, frequency-tripled Nd:YAG laser and fulfills a set of demanding requirements in terms of pulse energy, pulse length, repetition rate, and spatial and spectral beam properties. In particular, the frequency stability of the laser emission is an essential parameter which determines the performance of the lidar instrument as the Doppler frequency shifts to be detected are on the order of 108 smaller than the frequency of the emitted UV light. This article reports the assessment of the ALADIN laser frequency stability and its influence on the quality of the Aeolus wind data. Excellent frequency stability with pulse-to-pulse variations of about 10 MHz (root mean square) is evident for over more than 2 years of operations in space despite the permanent occurrence of short periods with significantly enhanced frequency noise (> 30 MHz). The latter were found to coincide with specific rotation speeds of the satellite's reaction wheels, suggesting that the root cause are micro-vibrations that deteriorate the laser stability on timescales of a few tens of seconds. Analysis of the Aeolus wind error with respect to European Centre for Medium-Range Weather Forecasts (ECMWF) model winds shows that the temporally degraded frequency stability of the ALADIN laser transmitter has only a minor influence on the wind data quality on a global scale, which is primarily due to the small percentage of wind measurements for which the frequency fluctuations are considerably enhanced. Hence, although the Mie wind bias is increased by 0.3 m s−1 at times when the frequency stability is worse than 20 MHz, the small contribution of 4 % from all Mie wind results renders this effect insignificant (< 0.1 m s−1) when all winds are considered. The impact on the Rayleigh wind bias is negligible even at high frequency noise. Similar results are demonstrated for the apparent speed of the ground returns that are measured with the Mie and Rayleigh channel of the ALADIN receiver. Here, the application of a frequency stability threshold that filters out wind observations with variations larger than 20 or 10 MHz improves the accuracy of the Mie and Rayleigh ground velocities by only 0.05 and 0.10 m s−1, respectively, however at the expense of useful ground data.

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Section: Aladin Configuration and Measurement Principlementioning

confidence: 99%

Section: Aladin Configuration and Measurement Principlementioning

confidence: 99%

ALADIN laser frequency stability and its impact on the Aeolus wind error

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The two fully redundant laser transmitters, referred to as flight models A and B (FM-A, FM-B), are switchable by a flip-flop mechanism (FFM). Both lasers are realized as diode-pumped Nd:YAG lasers in master oscillator power amplifier configuration that are frequency-tripled to 354.8 nm emission wavelength (ESA, 2008;Cosentino et al, 2012, Cosentino et al, 2017Lux et al, 2020a). A nonplanar Nd:YAG ring laser, frequency-locked to an ultra-low-expansion cavity, provides narrowband seed radiation that is fiber-coupled into the folded cavity of the 80-cm long Q-switched master oscillator (MO).…”

Section: Aladin Configuration and Measurement Principlementioning

confidence: 99%

“…A nonplanar Nd:YAG ring laser, frequency-locked to an ultra-low-expansion cavity, provides narrowband seed radiation that is fiber-coupled into the folded cavity of the 80-cm long Q-switched master oscillator (MO). The MO cavity length is actively controlled by means of a piezo actuator in order to find the optimal condition for single longitudinal mode operation for each laser pulse (Cosentino et al, 2017). The cavity control scheme is based on the ramp-hold-fire technique (Henderson et al, 1986) which involves the detection of cavity resonances of the injected seed radiation while sweeping the cavity length and firing the Q-switch at the detected resonance position of the piezo actuator.…”

Section: Aladin Configuration and Measurement Principlementioning

confidence: 99%

ALADIN laser frequency stability and its impact on the Aeolus wind error

Lux

Lemmerz

Weiler

et al. 2021

Preprint

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Abstract. The acquisition of atmospheric wind profiles on a global scale was realized by the launch of the Aeolus satellite, carrying the unique Atmospheric LAser Doppler INstrument (ALADIN), the first Doppler wind lidar in space. One major component of ALADIN is its high-power, ultraviolet (UV) laser transmitter which is based on an injection-seeded, frequency-tripled Nd:YAG laser and fulfills a set of demanding requirements in terms of pulse energy, pulse length, repetition rate as well as spatial and spectral beam properties. In particular, the frequency stability of the laser emission is an essential parameter which determines the performance of the lidar instrument, as the Doppler frequency shifts to be detected are on the order of 108 smaller than the frequency of the emitted UV light. This article reports the assessment of the ALADIN laser frequency stability and its influence on the quality of the Aeolus wind data. Excellent frequency stability with pulse-to-pulse variations of about 10 MHz (root mean square) is evident for over more than two years of operations in space despite the permanent occurrence of short periods with significantly enhanced frequency noise (> 30 MHz). The latter were found to coincide with specific rotation speeds of the satellite's reaction wheels, suggesting that the root cause are micro-vibrations that deteriorate the laser stability on time scales of a few tens of seconds. Analysis of the Aeolus wind error with respect to ECMWF model winds shows that the temporally degraded frequency stability of the ALADIN laser transmitter has only minor influence on the wind data quality on a global scale, which is primarily due to the small percentage of wind measurements for which the frequency fluctuations are considerably enhanced. Hence, although the Mie wind bias is increased by 0.3 m·s−1 at times when the frequency stability is worse than 20 MHz, the small contribution of 4 % from all wind results renders this effect insignificant (

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High-power and frequency-stable ultraviolet laser performance in space for the wind lidar on Aeolus

et al. 2020

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Global acquisition of atmospheric wind profiles using a spaceborne direct-detection Doppler wind lidar is being accomplished following the launch of European Space Agency’s Aeolus mission. One key part of the instrument is a single-frequency, ultraviolet laser that emits nanosecond pulses into the atmosphere. High output energy and frequency stability ensure a sufficient signal-to-noise ratio of the backscatter return and an accurate determination of the Doppler frequency shift induced by the wind. This Letter discusses the design of the laser transmitter for the first Doppler wind lidar in space and its performance during the first year of the Aeolus mission, providing valuable insights for upcoming space lidar missions.

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High energy, single frequency, tunable laser source operating in burst mode for space based lidar applications

Cited by 4 publications

References 4 publications

ALADIN laser frequency stability and its impact on the Aeolus wind error

ALADIN laser frequency stability and its impact on the Aeolus wind error

ALADIN laser frequency stability and its impact on the Aeolus wind error

High-power and frequency-stable ultraviolet laser performance in space for the wind lidar on Aeolus

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