ECD and CEL options
The laser cavity of MOGLabs lasers are hermetically sealed to reduce sensitivity to the effects of drafts and noise. Condensation due to operation at low temperatures will also be minimised inside the cavity. Note that the seal is not vacuum tight.
The figure below shows the frequency change with time for an open cavity laser (see Hawthorn et al.) compared to the MOGLabs monoblock laser with hermetic seal. The wild excursions seen with the open cavity laser are due to someone walking around near the two laser systems; the MOGLabs laser is unaffected.
When tuning the laser wavelength of the MOGLabs ECD004 Littrow laser, the output beam direction will change. This is normally corrected with a beam-steering "fold mirror"; see for example Rev. Sci. Inst. 72(2): 4477 (2001). For normal scanning using the internal piezo actuator, the beam direction does not change, only when manually adjusting the grating angle. For some applications, the fold mirror may not be required and it adds marginally to vibration susceptibility.
Water cooling connections
The laser base has a water cooling channel. Water cooling is normally not required, quick-fit connectors are provided to allow easy water connection for labs at high temperature or with large temperature fluctuations.
External cavity diode lasers are extremely susceptible to optical feedback, and require some form of optical isolation for stable single-frequency operation. We offer Faraday isolators from various suppliers, for example the EOT with 4mm diameter aperture, typically 36dB isolation and over 90% transmission. Contact MOGLabs for more options.
Anti-reflection coated diodes
We offer a range of diodes depending on wavelength, availability, and cost. If you are working at 780nm, our 60mW (extra-cavity) diode offers outstanding value, with good spatial mode quality and mode-hop free tuning range of up to 40GHz. Most often we use diodes with ultra-low reflectivity coatings, for the ultimate performance: best spatial mode quality, smallest linewidth, and best tunability. They are available at a range of wavelengths and power ratings, in particular the 780nm 150mW and 200mW options: the one diode can operate from 767nm to 820nm, with up to 200mW extra-cavity power (i.e. useful user-output).
Diffraction gratings and filters
The diffraction grating (ECD) or filter (CEL) can be selected for maximum output power but larger linewidth and reduced MHFR, or for increased feedback and reduced output power, but improved linewidth and MHFR.
Atomic vapour cells
MOGLabs is pleased to stock a number of vapour cells. We keep standard rubidium (natural isotopic mix) and caesium cells, in sizes including [Cs] 15mm x 20mm (diam x length), [Rb] 15mm x 50mm, 20mm x 70mm, 25mm x 75mm.
Zeeman coil and mount
AC (peak centre) locking is easy with a MOGbox, for example by modulating the injection current. However, the linewidth is then increased. The MOGbox can also directly drive a coil around the vapour cell, to modulate the atomic resonance. MOGLabs can provide a PCB with vapour cell, coil, and impedance balance circuitry. The price includes Bode plot of tested frequency response. The vapour cell must be purchased separately.
High compliance voltage
For standard DLC202 controllers, the maximum voltage available to the laser diode is 6V at 100mA and 3.2V at 200mA. These are sufficient for most laser diodes in the visible and infrared spectrum.
Most blue, violet and UV diodes can also be driven with a standard DLC, but if required, higher compliance voltage is available as an option; please contact MOGLabs for details.
Extended temperature range
The default temperature range is 0°C to 30°C. The temperature controller has a safety limit of −5°C. If the detected temperature is below −5°C or above 30°C, the temperature controller disables the TEC output to prevent overheating of the TEC.
The range and safety limit can be altered in the factory at no charge; please specify the desired range on your order. Note that large temperature ranges can make it tedious to set exactly the right temperature, and will have some impact on stability. The temperature range and limit can be altered by the end-user with a couple of minor resistor changes.
The default photodetector has filtered photodiodes, with transmission from 750 to 1100nm, and a narrow viewing angle (±10°). These are inherently insensitive to laboratory lighting and sunlight, and the narrow viewing angle further reduces background noise. For lasers operating in the visible range, photodiodes with sensitivity down to 350nm can be supplied at no charge. Wider viewing angles of ±20° or ±75° can also be supplied at no charge. Contact MOGLabs if you require operation outside the 350nm to 1120nm spectrum.
Laser headboard mounting plate
The MOGbox electronics includes a laser headboard, with protection circuits, RF bias tee, and breakout connectors to make it easy to connect your laser. MOGLabs can provide a mechanical mounting plate, with machined holes for the main connector, LED indicator lamp, and RF injection SMA connector. Two types are available: one is a direct replacement for the endplate of a Toptica DL100 laser; the other is a simpler laser-cut anodised aluminium rectangle (76mm x 47mm x 2mm thick).
Several different headboards are available including the B1240 which provides active current modulation with very low phase lag, allowing sub-Hz cavity locking (see MenloSystems ORS using MOGLabs lasers, here). Additional laser headboards can be helpful if you have multiple lasers for each controller.
Additional MOGbox-to-laser cables can also be purchased. They are standard 2m long DVI-D DL (dual link) cables. You can obtain such cables elsewhere but please be careful to specify dual-link, and note that cheap cables can cause substantial oscillations in the piezo.
Rack mount kits
Rack mount kits for MOGLabs diode laser controllers are now available. They incorporate full extension ball-bearing runners to easily slide out from the rack, to access internals or rear-mounted cables. Retrofit your existing DLC or purchase as an option with your next order.