DFB pro

Distributed-feedback laser

Single-frequency laser with distributed-feedback diode
Available wavelengths: 633 nm, 760 nm .. 3500 nm
Mode-hop free tuning range: Up to 1400 GHz
Reliable operation even in harsh environments
3 laser heads – wide range of options

Distributed feedback (DFB) lasers unite wide tunability and high output power. The frequency-selective element – a Bragg grating – is integrated into the active section of the semiconductor and ensures continuous single-frequency operation. Due to the absence of alignment-sensitive components, DFB lasers exhibit an exceptional stability and reliability. The lasers work under the most adverse environmental conditions – even in the Arctic or in airborne experiments.

Three laser heads, designed specifically for DFB lasers, accommodate different diode packages: the compact DFB pro and its “big brother” DFB pro L integrate 9 mm or TO3-type diodes. The DFB pro BFY offers a dedicated laser head for butterfly-type diodes.

Owing to their wide continuous tuning range, DFB lasers lend themselves particularly to applications in atomic and molecular physics, gas sensing, phase-shifting interferometry, and continuous-wave terahertz generation.

For a selection of available DFB/DBR laser diodes, please refer to the online stock list. If you are interested in a wavelength not shown there, please inquire – TOPTICA can provide customized DFB systems at virtually any wavelength between 760 nm and 3500 nm.

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Specification

	DFB pro	DFB pro BFY
Center wavelengths	633 nm, 760 nm - 3500 nm	1064 nm .. 2000 nm *
Output power	2 .. 150 mW	10 .. 100 mW (fiber output)
Tuning range	2 .. 6 nm	2 .. 5 nm, mode-hop free

Additional Information

DFB pro: Available Wavelengths and output power

Thermal frequency tuning of a DFB pro

Absorption spectrum of water vapor, recorded with a thermally tuned DFB pro at 935 nm.

Options

Fiber Delivery	Fiber Delivery (FD) is optionally available with TOPTICA's patented fiber coupler FiberDock and a suitable polarization maintaining (PM) fiber. FiberDock provides highest single-mode fiber coupling efficiencies, easy alignment and at the same time highest stability. For most lasers, we specify a PER behind fiber of >20 dB with our Fiber Delivery option. Please also inquire about Long Life and High Power fibers as well as fiber splitters. Optical isolation is mandatory for fiber coupled diode laser systems.
Optical Isolation	Isolators are used to protect the laser diode against back reflections. This not only prevents damage to the diode but also ensures untroubled tuning and single-frequency operation. Fiber-coupling with angle-polished fibers (both ends) requires at least a single-stage isolator (> 30 dB). Double-stage isolators are needed if reflections from the experiment into the laser are expected. Fiber-coupling with non-angle-polished fibers also requires a double-stage isolator (> 60 dB).
Beam Shaping	To shape elliptical laser beams into round profiles, either an anamorphic prism pair (APP) or cylindrical lenses are used. The compression ratio is set at the factory.
Bias-T	The DL pro (HP) has two modulation inputs that allow current modulation frequencies of up to 150 MHz. A Bias-T allows even higher current modulation frequencies of up to several GHz, depending on the diode. It is also suited for seed lasers of TA or NLO systems but not for DL pro HP lasers.
Electronics Modules	A broad variety of electronic locking modules is available for frequency stabilization.

Thermal tuning
Typical range	> 1000 GHz		> 600 GHz
Typical speed	50 GHz / sec		25 GHz / sec
Typical rate	-25 GHz / K		-10 .. -15 GHz / K
Electric tuning
Typical range	50 GHz		> 25 GHz
Typical speed	Up to MHz frequencies		Up to MHz frequencies
Typical rate	1 .. 10 GHz / mA (@ 1 Hz speed)		0.3 .. 1.0 GHz / mA (@ 1 Hz speed)
Typical instantaneous linewidth	< 500 kHz
Output beam characteristics	Collimated, Ø 3 mm x 1 mm (1/e²; note: circular profile with Beam shaping / pro)		Circular, divergent, Fiber NA typ. 0.12
Output beam polarization	Linear, > 100:1		Linear, typ. 100:1
Fast modulation (AC and DC coupled)	Included	Included	Included
Beam shaping / pro	Optional	Optional	--
Optical isolators	Optional, 30 dB **	Optional, 30 dB or 60 dB	Included ***
Fiber coupling	SmartDock, optional	FiberDock, optional	Fiber pigtail
Fiber coupling efficiency: min. (typ.)	50% (60%)	50% (60%)	N.A.
Fiber coupling efficiency with beam shaping / pro	55% (65%)	55% (65%)	N.A.
Dimensions laser head (H x W x D)	45 x 90 x 165 mm****	90 x 90 x 240 mm****	55 x 130 x 165 mm
Weight laser head	2 kg	3 kg	1 kg
Typical wavelengths	633 nm	780 / 795 nm	1178 nm (butterfly)
	780 / 795 nm	852 / 895 nm	1.5 µm
	852 / 895 nm	1000-1100 nm	1.65 µm
	> 2 µm (free-beam, w/o isolator)	1178 nm	2 µm (butterfly)
Dimensions control unit (H x W x D)	154 mm x 450 mm x 348 mm
Weight control unit	9 kg
Operating voltage	100 .. 240 V~, 50/60 Hz (wide-range input)
Power consumption	Typ. < 50 W, max. 250 W
PC Interface	Ethernet
Environmental temperature	15 - 30 °C (operating), 0 - 40 °C (storage and transport)
Environmental humidity	Non condensing