Freedom Photonics (United States)

Watt-class semiconductor optical amplifiers (SOAs) in the wavelength range from 1500 nm to 1650 nm offer performance enhancements for various applications including remote sensing, optical communications, and LIDAR, with the potential to enable efficient, compact, and cost-effective system solutions. Recent technological advancements have enabled high power diffraction-limited output from diode laser amplifiers with a tapered architecture. Freedom Photonics has developed SOA packages with fiber-coupled output and free space output, delivering multi-watt continuous wave output power at 1550 nm and at 1650 nm. Device-level robustness test results and package-level environmental test results will be presented. The 1550 nm tapered laser devices have sustained >16,000 hours of ongoing stress testing with negligible degradation, indicating good reliability for commercial qualification.

We present a Watt-class high brightness 1550 nm tapered laser with a monolithically integrated DFB grating which provides high power narrow linewidth light in a single chip. Over 2 W of single spatial- and spectral-mode power has been demonstrated with peak efficiencies over 30%.

Watt-class semiconductor optical amplifiers (SOAs) at 1550nm are an attractive alternative to replace erbium-doped fiber amplifiers (EDFAs) in various applications including free space optical communications (FSO), with the potential to be more efficient, compact, and cost-effective while providing high-power diffraction-limited output. We present a single mode fiber-coupled packaged SOA delivering >30dBm (1.2W) of continuous wave ex-fiber power at 1550nm with 16dB of overall gain, enabled by recent advancements in diffraction-limited output from tapered semiconductor amplifiers. Preliminary data communications measurements are presented, with an open eye diagram achieved with >1W of output power at 10Gbps using the differential phase shift keying (DPSK) communications format. Watt-class collimated and fiber-coupled SOAs are available and being shipped to customers now.

Rare-earth ion defects in solid-state hosts have emerged as a promising candidate for emissive quantum memories owing to their inherent spin–photon interface and long optical and spin coherence times. Erbium (Er³⁺) in particular has optical transitions in the C-band making it well suited to the use of existing telecom technology infrastructure. In this work, we present a platform to integrate rare-earth ions into standard silicon photonic circuits. Erbium is co-deposited in CMOS-compatible TiO₂ host films onto SOI and patterned into high Purcell factor photonic crystal cavities. Purcell factors in excess of 500 are observed and transient spectral hole burning and photoluminescence excitation scans reveal homogeneous linewidths below 15 MHz. Additionally, we show that photonic wirebonding can provide a solution for low-loss and thermally stable fiber-to-chip coupling.

Serotonergic psychedelics are gaining increasing interest as potential therapeutics for a range of mental illnesses. Compounds with short-lived subjective effects may be clinically useful because dosing time would be reduced, which may improve patient access. One short-acting psychedelic is 5-MeO-DMT, which has been associated with improvement in depression and anxiety symptoms in early phase clinical studies. However, relatively little is known about the behavioral and neural mechanisms of 5-MeO-DMT, particularly the durability of its long-term effects. Here we characterized the effects of 5-MeO-DMT on innate behaviors and dendritic architecture in mice. We showed that 5-MeO-DMT induces a dose-dependent increase in head-twitch response that is shorter in duration than that induced by psilocybin at all doses tested. 5-MeO-DMT also substantially suppresses social ultrasonic vocalizations produced during mating behavior. 5-MeO-DMT produces long-lasting increases in dendritic spine density in the mouse medial frontal cortex that are driven by an elevated rate of spine formation. However, unlike psilocybin, 5-MeO-DMT did not affect the size of dendritic spines. These data provide insights into the behavioral and neural consequences underlying the action of 5-MeO-DMT and highlight similarities and differences with those of psilocybin.

Q-switched Nd-based lasers are used for a variety of medical and manufacturing applications and require extremely high efficiency and stability from the diode pump, but limited commercially available solutions exist for single spatial mode direct pumping of Nd-based lasers at 885 nm. To satisfy this need, Freedom Photonics has developed ultra-robust watt-class diffraction-limited 885 nm diode lasers. We are in the process of performing full reliability and lifetime assessments on our watt-class single-mode 885 nm diode lasers. To achieve high reliability, we employ facet passivation methods to protect against catastrophic optical mirror damage (COMD). Additionally, progress on the development of VBG-locked packages will be discussed. These devices may be used as reliable, high efficiency pumps for Nd-doped solid-state lasers.

We demonstrate a Bell state analyzer that operates directly on frequency mismatch. Based on electro-optic modulators and Fourier-transform pulse shapers, our quantum frequency processor design implements interleaved Hadamard gates in discrete frequency modes. Experimental tests on entangled-photon inputs reveal fidelities of ∼ 98 % for discriminating between the | Ψ + ⟩ and | Ψ − ⟩ frequency-bin Bell states. Our approach resolves the tension between wavelength-multiplexed state transport and high-fidelity Bell state measurements, which typically require spectral indistinguishability.

Q-switched Nd-based lasers are used for a variety of medical and manufacturing applications and benefit from a high efficiency and stable diode pump, but limited commercially available solutions exist for single spatial mode direct pumping of Nd-based lasers at 885 nm. To satisfy this need, Freedom Photonics has developed ultra-robust watt-class diffractionlimited 885 nm diode lasers. We have demonstrated single-mode 885 nm diode lasers with an output power of <1.8 W (1 W rated) and 49% electricalto-optical efficiency. We employ facet passivation methods to protect against catastrophic optical mirror damage (COMD), and the optical power density we have demonstrated points to an effective facet passivation strategy. These devices may be used as high efficiency pumps for Nd-doped solid-state lasers.

Recent advancements in diffraction-limited output from tapered diode laser amplifiers represent a disruptive technology breakthrough that is poised to revolutionize the LIDAR market. Output powers which were previously only achievable using doped fiber, glass, or crystal laser architectures are now possible directly from the semiconductor chip. For example, diffraction-limited an output power of just a few watts at 1550 nm is sufficient for continuous wave frequency modulated (FMCW) automotive LIDAR. We report here a new world record of >3.0 W output power with nearly diffraction-limited beam quality (M^2 ~1.2) from a 1550 nm tapered diode laser amplifier; this source is suitable for direct use in numerous LIDAR and remote sensing applications.