This PDF file contains the front matter associated with SPIE Proceedings Volume 12092, including the Title Page, Copyright information, Table of Contents and Conference Committee list.

For portable spectroscopic systems, there is a high demand for smaller and economical laser modules. Heat management is essential in high-energy laser systems, but the “classic” external cooling methods are increasing the overall size of the laser. To avoid this problem, we implemented a “static”, non-circulated liquid cooling system. The laser cavity is hermetically sealed after it is filled up with liquid, no external liquid container is necessary. In this work, we present the development of a compact, low price, high energy Q-Switched Nd:YAG laser using commercially available components.

We present recent results on high energy, high repetition rate 2090 nm Ho:YAG laser system resonantly pumped by the radiation of efficient Tm-doped CW fiber lasers. The laser consists of a master oscillator power amplifier (MOPA) with two additional amplification stages. We demonstrate maximum energy of 120 mJ per pulse with a 15 ns pulse width at 500 Hz, corresponding to a peak power of 8 MW. The results presented in a wide 100-1000 Hz range of repetition rates.

We present the concept of a cost-effective broadband SWIR-MIR mJ-level femtosecond laser source for hazardous gas detection by LIDAR based on multi-stage nonlinear conversion in readily available media. Developed affordable laser based on Yb:YAG rods with >10 mJ, ~1.2 ps output pulses at 1030 nm pump 3-stage OPCPA based on BiBO and simultaneously excite a supercontinuum in YAG for its seed. Output pulses amplified to >2 mJ in the wavelength range 1800 – 2400 nm with a pump-to-signal OPCPA conversion efficiency of ~30% after compression to <100 fs are used to generate rotational SRS in compressed nitrogen, hydrogen, or their mixtures to expand the spectrum beyond 3400 nm, limited by the spectrometer used.

Experiments on energy scaling and extending wavelength tunability of Dy:PGS and Dy:KPC lasers were undertaken. Both lasers demonstrated >1mJ output pulse energy under diode laser pumping. Dy:PGS laser wavelength tunability was extended to 4.68um, which is the longest wavelength of laser oscillation ever reported for this crystal under 1.7um diode pumping. The longest wavelength of laser oscillation with Dy:KPC crystal was 4.45um. Modelling of Dy:KPC and Dy:PGS laser operation in Q-switching mode was carried out. It was shown that Dy:KPC and Dy:PGS lasers are capable of producing Q-switch pulses with several kW peak power and pulse duration of ~ 40ns.

The signal-to-noise ratio (SNR) of a digital holography (DH) system is degraded by the total system efficiency, which is comprised of many terms. For pulsed-laser source DH systems, the total-system efficiency is dependent on the amount of temporal overlap between the signal and reference pulses. This temporal overlap not only accounts for the amplitudes of the pulses but also for the phase, which may cause degradations to the achievable SNR. A previous effort formulated a model for the effect of temporal overlap in terms of the ambiguity efficiency [Owens et. al., Appl. Opt., submitted for publication]. The outputs from the model were compared to measured results obtained using a 1064 nm pulsed-laser source DH system. Initial comparisons showed the model insufficiently accounted for one or more causes of performance degradation, leading to an over-prediction of performance. Two likely causes, mode hopping and linear frequency modulation (LFM), were investigated. It was found both could account for the over-prediction in the model, indicating the model used in the previous effort is valid.

The recent development of kW class blue lasers for commercial applications suggests that these lasers may also have a role in defense applications ranging from manufacturing to directed energy weapons. This paper will discuss how to scale today's blue laser technology to power levels necessary to achieve sufficient power for directed energy applications such as drone defense and hypersonic missile defense. The enhanced absorption characteristics of the blue laser light dramatically decreases the laser energy required on target to cause fatal damage to the target resulting in smaller and lighter systems with the same effectivity as larger IR laser systems. This paper will discuss the future uses of blue laser technology for applications such as drone defense.

U.S. Defense contractors have sought to find commercially available off the shelf (COTS) sources for over a decade which can perform to the Size, Weight, Power and Cost (SWAP-C) demands of DoD applications. In conjunction, the maturation of laser processing to increase throughput and yield throughout industry has led to continuous development of increasingly compact, powerful, reliable, and affordable laser systems. Although desirable to accelerate procurement and development timelines, rarely has it been feasible to directly plug industrial lasers into DoD applications. Typical high power industrial lasers require water cooling, have rack-mounted separate drive and control electronics, and are not designed for compactness in the manner defense lasers are. Using decades of experience in designing laser systems for both defense and general industry, Quantel USA has invested in the development of an industry leading high density, high power, nanosecond pulsed laser, with fully integrated electronics and programmable laser parameters. With the 7mW/cm³ density of the conductively cooled Shrike^TM laser, the prime contractors and integrators can now order COTS products which are designed to meet their SWaP-C, across the spectrum from UV to SWIR using flexible pulse parameters at greater than 5W of power. The continuous industrial production cycle will allow defense integrators to rapidly deploy both concept demonstrators and production volumes, while maintaining reliability and performance in military environments.

We report on two architectures for obtaining watt-level single mode output from a fiber laser at 2150 nm, one based on a diode-pumped Thulium fiber laser, and another based on a Thulium fiber laser pumped Holmium fiber laser. We observe temporal instability in the diode-pumped Tm-doped fiber system when operating at 2150 nm, with unstable pulsing, and a maximum power of 0.935 W. The Ho-doped fiber system pumped by Tm laser operating at the same 2150 nm wavelength shows periodic pulsing at a fixed rate of 21.25 MHz. Pulsing was observed as soon as the laser threshold was reached. Both laser systems operated in a single spatial mode.