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In this article, laser processing of diamondlike carbon‐metal nanocomposite films, hydroxyapatite‐osteoblast composites, and Ormocer® microdevices for medical applications is described. Pulsed laser deposition has been used to process diamondlike carbon‐silver‐platinum nanocomposite films that provide hardness, wear resistance, corrosion resistance, and antimicrobial functionalities to cardiovascular, orthopaedic, biosensor, and MEMS devices. Laser direct writing has been used for fabricating integrated cell‐scaffold structures. Two photon induced polymerization has been used to create Ormocer® tissue engineering scaffolds and microneedles with unique geometries. Pulsed laser deposition, laser direct write, and two photon induced polymerization techniques may provide medical engineers with advanced biomaterials that possess unique structures and functionalities.

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Modern environmental and sustainability issues as well as the growing demand for applications in the life sciences and medicine put special requirements to the chemical composition of many functional materials. To achieve desired performance within these requirements, innovative approaches are needed. In this work, we experimentally demonstrate that thermal strain can effectively tune the crystal structure and versatile properties of relatively thick films of environmentally friendly, biocompatible, and low-cost perovskite ferroelectric barium titanate. The strain arises during post-deposition cooling due to a mismatch between the thermal expansion coefficients of the films and the substrate materials. The strain-induced in-plane polarization enables excellent performance of bottom-to-top barium titanate capacitors akin to that of exemplary lead-containing relaxor ferroelectrics. Our work shows that controlling thermal strain can help tailor response functions in a straightforward manner.

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A 2-μm wavelength laser delivering up to 39-mJ energy, ∼10 ps duration pulses at 100-Hz repetition rate is reported. The system relies on chirped pulse amplification (CPA): a modelocked Er:Tm:Ho fiber-seeder is followed by a Ho:YLF-based regenerative amplifier and a cryogenically cooled Ho:YLF single pass amplifier. Stretching and compressing are performed with large aperture chirped volume Bragg gratings (CVBG). At a peak power of 3.3 GW, the stability was <1% rms over 1 h, confirming high suitability for OPCPA and extreme nonlinear optics applications. ultra-short mid-IR pulses, but further progress is hampered by the near exclusive usage of ∼1 μm pump lasers. These pump lasers impose an unfavorable photon ratio between pump and signal/idler that limits efficiency, prevents accessing the highly efficient class of non-oxide crystals, and presents serious power scaling limitations due to linear and two-photon absorption [12]. These limitations can be mitigated using powerful pump lasers emitting at 2-μm wavelength thereby reducing the photon ratio mismatch and allowing the use of highly nonlinear non-oxide crystals such as ZGP [13]. While the technology of such lasers, based on Q-switched Ho:YLF (or Ho:LuLiF) and Ho:YAG, is very mature for generating high-energy nanosecond pulses [14][15][16][17][18][19][20], amplification of few picosecond pulses from such systems to the multi-tens of mJ has not been reported. In this Letter, we report on a compact and stable laser system operating at 2-μm wavelength, delivering ∼10 ps duration optical pulses with up to 39-mJ output energy at 100-Hz repetition rate. Highly efficient temporal compression of narrow-band picosecond pulses was performed at the multi-tens of mJ energy-level in a chirped volume Bragg grating (CVBG).The laser system relies on chirped pulse amplification (CPA) architecture consisting of a fiber seeder, a CVBG stretcher, two consecutive amplification stages, and a large aperture CVBG compressor (Fig. 1). The all-fiber seeder is a multi-stage system (Menlo Systems GmbH) starting with an amplified modelocked Er:fiber oscillator delivering femtosecond optical pulses at 100-MHz repetition rate and 1.5-μm wavelength. These pulses are frequency shifted to 2052-nm wavelength and spectrally narrowed to ∼1.5 nm bandwidth before seeding a series of Tm:Ho fiber amplifiers [21]. The 4-nJ energy, picosecond duration pulses emerging from these amplifiers at 100 MHz form the seed for the CPA chain thereby removing the problem of modelocking Ho-based systems directly. These pulses are temporally stretched to 170-ps duration in a double-pass, CVBG-based stretcher. The CVBG (OptiGrate Corp.) used in this stretcher is broadband AR-coated around 2052 nm, has a 5 mm × 8 mm clear aperture, a chirp rate of 150 ps/nm, and a design wavelength of 2053.5 nm. Upon stretching, the 100-MHz train is passed through a rubidium titanyle phosphate (RTP) pulse picker to reduce the repetition rate to 100 Hz. The pulses are then passed through an optical isolator and directed toward a regen...