nanoplus Nanosystems and Technologies GmbH in Germany has expanded its range of available single mode DFB laser diodes up to a wavelength of 2.75µm. Especially for diode laser based spectroscopy these new diodes give access to higher absoption levels in the NIR range (e.g. water or HF).
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Fig. 1: Emission of of a 2741 nm DFB Laser diode. |
The laser diodes operate at room temperature in cw mode with a single mode output power of several mW. Typical side mode suppression rates of this laser diodes are >30dB. The laser line can be tuned by current or temperature with tuning rates of 0.025nm/mA and 0.21nm/°C respectively.
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| Fig 2: I-P Characteristic of a 2741 nm DFB Laser diode. |
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Fig. 3: Tuning of the emission wavelength of a 2741 nm DFB with current and temperature. |
Nanoplus offers a variety of mounting options for the laser diodes. The diodes can be mounted on standard TO headers like TO9mm, TO5.6. Beside these headers nanoplus offers also the option of an integrated peltier and NTC in a sealed TO8 header.
Applications
These 2.7µ DFB-Laser diodes are well suited for Tunable Diode Laser Spectroscopy (TDLS). As an example for strong absorption lines
in the 2.7 µm region you can see in Fig. 4 the absorption of NO, which is much stronger in the 2.7 µm compared to the 1.8 µm
region.
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Fig 4: Aborption spectrum of nitrogen oxide arround 2700 nm. |
Around 2.7 µm is the fundamental rotational-vibrational mode of water. This leads to very strong aborption lines for water in region ranging from approx. 2.4 µm to 3.0 µm.
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Fig. 5: Absorption of water vapor at the fundamental rotational-vibrational absorption region. |
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