Compact and robust external-cavity diode laser (ECDL) systems are a mandatory requirement for many next-generation quantum technology applications, e.g. quantum communication and quantum sensors. Today’s commercially available ECDLs are used for proof-of-principle demonstrations of such applications, however do not meet the requirements for the use in real-world environments. We investigate a novel design for a compact and robust ECDL suitable for the integration into first quantum technology applications. Experimental results of first prototypes are presented and compared to a commercially available ECDL and numerical simulations.
Several holographic and interferometric applications would benefit significantly from a diode laser based coherent light source near 633 nm. For this purpose a miniaturized master-oscillator power-amplifier (MOPA) was developed. The MOPA is integrated in a sealed package together with a custom-built CdMnTe-based micro-optical isolator to shield the MO from optical feedback. The MOPA reaches an optical output power of up to 30 mW near 633 nm. Its single-mode emission is tunable over 0.5 nm by temperature and 1.0 nm by a grating heater. The package offers the integration of a gas cell and a polarization maintaining fiber port.
This work reports on a compact diode-laser module emitting at 633 nm. The emission frequency can be tuned with temperature and current, while optical feedback of an internal DBR grating ensures single-mode operation. The laser diode is integrated into a micro-fabricated package, which includes optics for beam shaping, a miniaturized optical isolator, and a vapor cell as frequency reference. The achieved absolute frequency stability is below 10<sup>−8</sup> , while the output power can be more than 10 mW. This compact absolute frequency-stabilized laser system can replace gas lasers and may be integrated in future quantum technology devices.
This work reports on a compact single-mode diode laser emitting at 633 nm based on an AlGaAs/AlGaInP structure with an integrated DBR surface grating. The micro-fabricated diode laser package includes optics for beam shaping, optical isolation and single-mode fiber coupling. The miniaturized optical isolator is based on cadmium manganese telluride, which provides a large Verdet constant and thus enables the realization of a compact Faraday rotator in the visible spectral range. We discuss the performance and the technological challenges for this approach. Furthermore, we present prospects towards the integration of atomic reference cells into compact laser systems. This would enable the realization of absolute frequency-stabilized diode lasers that could be used in quantum technology devices.
Several holographic and interferometric applications would benefit significantly from a diode laser based coherent light source near 633 nm. For this purpose a laser diode based on an AlGaAs/AlGaInP structure for emission in the red spectral range was developed. The laser chip features a ridge waveguide and a DBR surface grating at the rear side with a peak reflectivity at 633 nm. The laser was mounted in a butterfly-style package for temperature stabilization. The beam emitted by the laser diode was shaped with two cylindrical micro-lenses and passed through a custom-built CdMnTebased micro-optical isolator. The beam behind the isolator was coupled into a polarization maintaining (PM) single-mode fiber using an aspherical lens. The optical output power of the fiber was about 1.7 mW at 100 mA.