Widely Tunable Vertical Cavity Lasers

Optical Spectrum of widely-tuned laser, showing lasing over 150 nm around 1310 nm, overlaid with continuously-tuned spectrum.

Optical spectrum of widely-tuned VCSEL, showing lasing over 150 nm around 1310 nm.

MEMS-VCSEL Schematic

Schematic of the mechanically-tunable vertical-cavity laser (MEMS-VCSEL).
The device is less than 1mm across.

Widest & Fastest Tunable 1310nm VCSEL to-date:

Widest tuning electrically-pumped 1060nm MEMS-VCSEL, producing high-quality ophthalmic images:

First Tunable 1060nm VCSEL:

 

State-of-the-art Light Sources for high resolution & meter-range 3-D imaging:

Praevium Research has recently developed record widely tunable Vertical Cavity Lasers (VCSELs) with tuning ranges of up to 150nm (see spectra at left) near 1310nm.
The 1050nm version stands out as one of the few tunable 1050nm laser sources available, with up to 100nm of tuning.
The single-mode nature of these sources results in extremely long coherence lengths (≥200 meters), enabling long-range 3-D imaging in addition to high-speed ophthalmic & endoscopic imaging.

Under NCI grant 2R44CA101067-05, in conjunction with commercial partner Thorlabs and academic partner MIT, these devices are being developed for emerging swept-source optical coherence tomography (SS-OCT) systems.

VCSELs provide an ideal source for OCT, as the combination of short cavity length and small mirror mass enable extremely high wavelength sweep rates needed for real-time volumetric imaging.
In addition, in contrast to other swept sources for OCT, truly single-mode operation enables narrow dynamic linewidth, which translates to long coherence length for deep imaging.

Praevium Research, Inc, in collaboration with MIT and Thorlabs, Inc., presented the first VCSEL/OCT results at a post deadline session at CLEO 2011 in Baltimore, MD, and more recently, featured the results in Electronics Letters (see links above).

In 2015 we published the first ophthalmic images taken with a new electrically-pumped MEMS-VCSEL. See the 2015 JLT paper for ophthalmic dye-free angiography and high-resolution images, measurements of the long coherence length and the benefits of spectral shaping with the Praevium-designed wide-band optical amplifier (BOA).

At OFC 2014 in San Francisco, Praevium demonstrated our first MEMS-VCSEL operating at 1550 nm.  This device is still in the prototyping phase, but initial results show C-band & L-band coverage with a tuning bandwidth >150 nm at up to 390 kHz sweep rate.

Tuning Spectrum of the prototype 1550nm MEMS-VCSEL.

Tuning spectrum of the prototype 1550nm MEMS-VCSEL with 170nm span.

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