Single-photon generation

Single photons can be used as information carriers in, e.g., quantum key distribution schemes or as qubits in photonic quantum computers.

A key building block in quantum information technology is single-photon sources which, as the name suggests, can emit a single photon – spontaneously or carefully timed.

Typically, when you want to generate single photons, you reduce the output power of your laser to the point where it emits a single photon at a time. Due to the random nature of this approach, the laser emits photons spontaneously and unpredictably, which has advantages and drawbacks.

Pulsed lasers ensure predictable emission

You can use a pulsed laser to pump fluorescent nanoparticles to ensure a predictable emission of single photons. You can make nanoparticles in various shapes and sizes, depending on the material. The shape and size affect the optical properties of the nanoparticle.

For a given application and nanoparticle design, you need a specific wavelength and pulse duration combination to pump and operate the nanoparticle. You will typically need wavelengths in the VIS to NIR region.

Pick the right laser

No matter how you have designed your nanoparticles, we have the right laser for you:

  • For characterization and research – where you need flexible wavelengths and excitation bandwidth of wavelength – our SuperK CHROMATUNE tunable laser is a turnkey picosecond pulsed laser with a built-in filter. Get any wavelength from 400 nm-1000 nm in one laser.
  • For specific wavelengths, our PILAS diode lasers give you high-performance cost-efficient picosecond pulsed light at a wide range of wavelengths. Pick the one you need.
PILAS picosecond lasers

We are part of the European Quantum Flagship, the European Quantum Industry Consortium, the Quantum Economic Development Consortium, and the Danish Quantum Community.

Accurate quantum gravity sensors

Quantum gradiometers, gravity sensors, or gravimeters, allow you to accurately map local variations in gravity to ensure infrastructure integrity and safer constructions. They are great tools for, e.g., civil engineers, land surveyors, and railroad companies.

The most sensitive gravity sensors use atom interferometry on atoms cooled close to absolute zero and placed in a free fall. In a free fall, the distance traveled over a period of time is determined by the local gravitational pull.

You need accurate lasers to cool atoms

Laser cooling is a critical step that requires a tunable narrow-linewidth high-power laser such as our Koheras BASIK. Rubidium atoms are typically cooled in a magneto-optical trap, MOT. A MOT uses a combination of magnetic fields and a narrow-linewidth high-power laser at 780 nm to cool and trap the atoms and place them in an appropriate quantum state for further investigation by, e.g., atom interferometry.

We shoot light pulses at atoms as they undergo free fall. Each atom has a certain probability of absorbing a light pulse, and if it does, it slows down. The atoms that are slowed down do not travel as far as those not slowed down, which leads to two vertically separated outcomes with a relative distance determined by the gravitational pull.

Rubidium atoms are often used in gravitational sensors. If you carefully observe the free-fall acceleration, you can determine the local gravity and reveal even the tiniest variations created by dense objects or underground cavities.

Pick a stable laser

When you look for a laser for a gravitational sensing system, pick a stable one. The system will be moved around a lot and must keep its stability and precision. A fiber laser is a good choice because it contains no moving parts and is intrinsically stable.

The Koheras DFB fiber lasers are well known for their unmatched Hz-level linewidth at watt-power levels. But DFB fiber lasers only come in a few infrared wavelength bands. And these bands rarely match the wavelengths needed for laser cooling of atoms and ions.

Frequency conversion gives you 780 nm

We suggest seeding an Erbium-Doped Fiber Amplifier (EDFA), such as the Koheras BOOSTIK HP, with a stable narrow linewidth seed laser such as the Koheras BASIK at 1560 nm. Use the Koheras HARMONIK frequency conversion module to efficiently convert the high-power light at 1560 nm into high-power light at 780 nm.

You get a 780 nm fiber laser system at watt level with a beam quality M2 ≈ 1.1 and a free-running linewidth less than 1 kHz – the ideal laser system for any Rb atom interferometer.

Frequency conversion is a nonlinear process. The HARMONIK frequency conversion module only converts the main laser signal while cleaning up any unwanted power at out-of-band wavelengths present in most lasers.

Robust enough for oil rigs yet sophisticated enough for the lab

Our fiber laser design is inherently compact and robust. It is developed for a lifetime of above 10 years in demanding environments where uptime is critical. With failure rates lower than 1%, we proudly deliver the most reliable low-noise lasers on the market. Alignment-free and maintenance-free.

The industrial-grade OEM lasers have a rugged design, a stable performance unaffected by changing environmental conditions, and wide temperature ranges in the field as well as the lab. We deliver lasers to the most advanced laboratories worldwide such as the UK Quantum Technology Hub for Sensors and Timing at the University of Birmingham and the Institute of Quantum Optics at Leibniz University Hannover.

We have more than 15,000 Koheras lasers deployed in the harshest environments on – and off – the planet. We have lasers on oil rigs, submarines, wind turbines, and even in space. With over 20 years of experience, we know they last. Also in your lab.

References

Our quantum engagements

We are part of the European Quantum Flagship, the European Quantum Industry Consortium, the Quantum Economic Development Consortium, and the Danish Quantum Community.

Accurate quantum inertial sensors

If you can track your rotation and acceleration in any direction over time, you can calculate your exact position and velocity relative to your starting point – without relying on external input such as GPS or landmarks.

The accuracy of your inertial sensor determines the accuracy of your position and velocity derived from the measured acceleration. Today, the most accurate inertial sensors are based on atom interferometry which is created by cooling and manipulating individual (typically alkaline) atoms with laser beams.

A popular choice of atom for atom interferometry is Rubidium-87 which requires a high power 780 nm beam of light with narrow linewidth and high beam quality.

You need accurate lasers to cool atoms

Laser cooling is a critical step that requires a tunable narrow-linewidth high-power laser such as our Koheras BASIK. The rubidium ions are typically cooled in a magneto-optical trap, MOT. A MOT uses a combination of magnetic fields and a narrow-linewidth high-power laser at 780 nm to cool and trap the ions to place them in an appropriate quantum state for further investigation by, e.g., atom interferometry.

Atom interferometry

Atom interferometry uses the wave property of atoms to place an atom in a superposition between two states: One state where the atom has been “hit” by a light pulse, and one where it was not. Something that will send the two states along different paths.

Just as light, these two states can undergo interference if brought back together. Any perturbation along their paths, such as the forces from rotational or translational acceleration will affect how the matter-wave interference pattern turns out.

Pick a stable laser

The Koheras DFB fiber lasers are well known for their unmatched Hz-level linewidth at watt-power levels. But DFB fiber lasers only come in a few infrared wavelength bands. And these bands rarely match the wavelengths needed for laser cooling of atoms and ions.

Frequency conversion gives you 780 nm

We suggest seeding an Erbium-Doped Fiber Amplifier (EDFA), such as the Koheras BOOSTIK HP, with a stable narrow linewidth seed laser such as the Koheras BASIK at 1560 nm. Use the Koheras HARMONIK frequency conversion module to efficiently convert the high-power light at 1560 nm into high-power light at 780 nm.

You get a 780 nm fiber laser system at watt level with a beam quality M2 ≈ 1.1 and a free-running linewidth less than 1 kHz – the ideal laser system for any Rb atom interferometer.

Frequency conversion is a nonlinear process. The HARMONIK frequency conversion module only converts the main laser signal while cleaning up any unwanted power at out-of-band wavelengths present in most lasers.

Robust enough for oil rigs and sophisticated enough for the lab

Our fiber laser design is inherently compact and robust. It is developed for a lifetime of above 10 years in demanding environments where uptime is critical. With failure rates lower than 1%, we proudly deliver the most reliable low-noise lasers on the market. Alignment-free and maintenance-free.

The industrial-grade OEM lasers have a rugged design, a stable performance unaffected by changing environmental conditions, and wide temperature ranges in the field as well as the lab. We deliver lasers to the most advanced laboratories worldwide such as the Institute of Quantum Optics at Leibniz University Hannover and the UK Quantum Technology Hub for Sensors and Timing at the University of Birmingham. We have more than 15,000 Koheras lasers deployed in the harshest environments on – and off – the planet. We have lasers on oil rigs, submarines, wind turbines, and even in space. With over 20 years of experience, we know they last. Also in your lab.

References

Our quantum engagements

We are part of the European Quantum Flagship, the European Quantum Industry Consortium, the Quantum Economic Development Consortium, and the Danish Quantum Community.

Trapped Beryllium ions

To cool down a 9Be+ ion, you need a kHz-linewidth low-noise 313 nm laser. A narrow-linewidth low-noise laser is essential if you want to trap beryllium ions at exotic wavelengths, such as 313.

By combining low-noise fiber lasers and multiple frequency conversion steps, it is now possible to produce 313 nm at high power with all the benefits of fiber lasers usually reserved for infrared applications.

Get 313 nm

313 nm can be reached in a two-step frequency-conversion process using two DFB fiber lasers: A Koheras BASIK Y10 at 1051 nm and a Koheras BASIK E15 at 1550 nm and our new Koheras HARMONIK frequency-conversion module.

Our new HARMONIK turn-key module uses sum-frequency generation (SFG) to get 626 nm and subsequent second-harmonic generation (SHG) to reach 313 nm at watt power level.

This lets you transfer amplified high-quality, narrow-linewidth, stable, low-noise light from infrared fiber lasers to the 313 nm region. This nonlinear conversion process efficiently quenches out-of-band power, such as amplified spontaneous emission (ASE), that is present in any amplified laser system and usually adds high-frequency phase noise.

Have a quick look at these key specifications to see if the Koheras HARMONIK would work for you:

HARMONIKH31
Output power> 1 W
Linewidth< 40 Hz
Total thermal tuning range± 70 pm

See all the Koheras HARMONIK frequency-conversion module specifications on the product page.

This laser is robust enough for oil rigs yet sophisticated enough for the lab

Our fiber laser design is inherently compact and robust. It is developed for a lifetime of above 10 years in demanding environments where uptime is critical. With failure rates lower than 1%, we proudly deliver the most reliable low-noise lasers on the market. Alignment-free and maintenance-free.

The industrial-grade OEM lasers have a rugged design, a stable performance unaffected by changing environmental conditions, and wide temperature ranges in the field as well as the lab. We deliver lasers to the most advanced laboratories worldwide such as the National Institute of Standards and Technology and the Institute for Trapped-Ion Quantum Engineering Group at Leibniz University Hannover.

We have more than 15,000 Koheras lasers deployed in the harshest environments on – and off – the planet. We have lasers on oil rigs, submarines, wind turbines, and even in space. With over 20 years of experience, we know they last. Also in your lab.

Unique fiber delivery system 

Do you want to mount the laser system in a rack? No problem. With our unique fiber delivery system, aeroGUIDE POWER, you can get light wherever you want. The fiber delivery solution handles high power, preserves the low-noise laser properties, and delivers single-mode light at all wavelengths.  

References

Our quantum engagements

We are part of the European Quantum Flagship, the European Quantum Industry Consortium, the Quantum Economic Development Consortium, and the Danish Quantum Community.

Use lasers to make quantum computers

You can use cold-atom systems as quantum computers. Cooling lasers freeze atoms and hold them still, mid-air, using Doppler cooling and dipole trapping techniques. The cold atoms are manipulated, entangled, and read using more lasers and optical techniques to form highly attractive qubits in quantum computers.

Pick the right laser for quantum computing

When choosing a laser for atom trapping, cooling, and manipulation, there are several things to consider:

Power scalability

Power consumption of cold atom/ion experiments scale with the number of qubits. Diode lasers have a breaking point at 2-4 W before compromising linewidth or system temperature, while our fiber lasers routinely supply >15 W of narrow linewidth power without breaking a sweat.

Narrow linewidth

Linewidth is closely tied to laser technology. Phase noise in the system leads to the broadening of the linewidth.

For Doppler cooling, the laser’s linewidth must be significantly smaller than the linewidth of the atom. Otherwise, the laser – not the atom – will determine how low a temperature we can obtain. Similarly, intensity fluctuations – typically expressed as relative intensity noise (RIN) – also heat the atom and limit its cooling rate.

Our fiber lasers have linewidths in the 1-100 Hz range, making them the narrowest linewidth lasers commercially available.

Wavelength coverage

Specific and hard-to-reach wavelengths are the key to the quantum computing market. Our lasers cover most of the wavelengths in the visible spectrum as well as those for infrared transitions of, e.g., barium.

Wavelength stability

It is critical to ensure accurate wavelength control when you pick a laser for the narrow transitions of cold atom experiments. To fine-tune the system, the absolute wavelength must be well-defined, adjustable, and stable.

The Koheras fiber laser systems allow coarse thermal tuning of the laser cavity and fast piezo tuning for locking in, e.g., a Pound-Drever-Hall scheme.

Fiber advantages

Fiber coupling is necessary if you want to rack mount your laser system. Fiber lasers have single-mode fiber output and are inherently more beam-stable than other laser types. Moreover, NKT Photonics’ photonic crystal fiber platform is uniquely suited to transport single-mode, high-power, narrow-linewidth light at all power levels we provide.

So if you want to mount the laser system in a rack, it is not a problem. With our unique fiber delivery system, aeroGUIDE POWER, you can get light wherever you want.

Scalable & industrial manufacturing

The fiber laser platform is highly scalable. We have experience in scaling and delivering thousands of lasers every year.

Our fiber laser architecture builds on 20 years of experience with over 15,000 single-frequency fiber lasers in the field, many in harsh environments running 24/7. The Mean Time Between Failure for the lasers is >30 years.

A laser that checks all these boxes – and more – is our Koheras HARMONIK. We have developed it specifically for trapping and cooling atoms for quantum optic applications.

Our quantum engagements

We are part of the European Quantum Flagship, the European Quantum Industry Consortium, the Quantum Economic Development Consortium, and the Danish Quantum Community.

How do you make cold atoms?

When you want to cool and trap atoms with lasers, you need to know that – at the atomic scale – temperature makes atoms wiggle around. Reducing their movement is the same as reducing their temperature. You can cool atoms by carefully matching your atom with a laser that can emit light with the properties needed to cool that specific atom.

To cool an atom, you make it absorb energy only when it randomly moves towards the laser. After a short while, the atom begins to reemit the absorbed light in random directions. On average, this makes the atom slow down in the direction of the laser because it loses net kinetic energy in that direction.

Now you add a beam in all three dimensions, and the atom will be forced to slow down in all directions. This technique lets you cool the atom down to well below 1°K, depending on the type of atom.

The goal is to make the atom absorb light only when moving in a specific direction. Atoms can only absorb light if the light is oscillating at one of the discrete frequencies allowed by the atom. For rubidium, one of these frequencies corresponds to light with a wavelength of 780 nm. If the wavelength is longer, the rubidium atom will not absorb it.

In a laser Doppler cooling system, the wavelength of the laser must be slightly longer than required for absorption. When the atom moves toward the laser, the Doppler effect will cause the atom to experience the laser as emitting light at a shorter wavelength due to the Doppler effect. The atom will absorb a photon.

When moving away from the laser source, the atom experiences the wavelength as longer and nothing happens. You can use a magneto-optical trap (MOT) to shoot light at the atom from both directions and in all three dimensions. This cools rubidium atoms down to a few µK and they are ready to be put to work.

In some systems, the atoms are transferred to other laser cooling systems to lower the temperature further before they are used.

Get the high power, low noise, and wavelength conversion with the Koheras BOOSTIK HP

With the stable, high-power Koheras fiber lasers, you get the best starting point for a successful implementation of optical tweezers or standing wave-type dipole traps. Due to the 15 W output power, low noise, and single-mode fiber delivery, setting up has never been easier.

Use the Koheras BOOSTIK HP with our efficient and stable wavelength conversion module, the Koheras HARMONIK, to address the dipole trapping wavelengths of your favorite atoms such as strontium or rubidium. Wavelength conversion also quenches any ASE in the laser system and ensures a spectrally pure signal.

With its high power, ASE suppression through conversion, lack of chillers, and fiber-delivered light, the Koheras lasers are ideal for dipole trapping in the lab and the rack.

HARMONIKH81
Center wavelength789-845 nm
Output power> 3 W
RIN level< -100 dBc/Hz @ peak
< -140 dBc/Hz @ 10 MHz
Optical S/N (50 pm res.)> 70 dB

Go to the HARMONIK product page for more information.

Unique fiber delivery system 

Do you want to mount the laser system in a rack? No problem. With our unique fiber delivery system, aeroGUIDE POWER, you can get light wherever you want. The fiber delivery solution handles high power, preserves the low-noise laser properties, and delivers single-mode light at all wavelengths.  

This laser is robust enough for oil rigs yet sophisticated enough for the lab

Our fiber laser design is inherently compact and robust. It is developed for a lifetime of above 10 years in demanding environments where uptime is critical. With failure rates lower than 1%, we proudly deliver the most reliable low-noise lasers on the market. Alignment-free and maintenance-free.

The industrial-grade OEM lasers have a rugged design, a stable performance unaffected by changing environmental conditions, and wide temperature ranges in the field as well as the lab. We deliver lasers to the most advanced laboratories worldwide such as the Center of Applied Space Technology and Microgravity at the University of Bremen and the National Ignition Facility at Lawrence Livermore National Laboratory.

We have more than 15,000 Koheras lasers deployed in the harshest environments on – and off – the planet. We have lasers on oil rigs, submarines, wind turbines, and even in space. With over 20 years of experience, we know they last. Also in your lab.

References

We are part of the European Quantum Flagship, the European Quantum Industry Consortium, the Quantum Economic Development Consortium, and the Danish Quantum Community.

Get the ultra-low noise and high power from Koheras lasers and amplifiers

You get a stable, narrow-linewidth fiber laser with intrinsically low phase noise from the Koheras BASIK E15 pump laser.

If you need an even lower relative intensity noise, order the RIN reduction option.

Have a quick look at the noise specification to see if the BASIK laser would work for you:

BASIKE15
Linewidth< 0.1 kHz
Max. phase noise-90 dB((Rad/√Hz)/m)@10Hz
-110 dB((Rad/√Hz)/m)@100Hz
-130 dB((Rad/√Hz)/m)@20kHz
Max. phase noise32 (µrad/√Hz)/m@10Hz
3.2 (µrad/√Hz)/m@100Hz
0.3 (µrad/√Hz)/m@20kHz
RIN peakAppr. 0.7 MHz
RIN level @ peak/10 MHz<-100 / <-135 dBc/Hz

The Koheras BOOSTIK HP fiber amplifier extends the output power of the pump laser. It gives you an output power of 15 W. It is the ideal choice for noise-sensitive applications such as squeezed light because it preserves the ultra-low phase noise and narrow linewidth of the Koheras BASIK seed lasers.

See all the specifications on the Koheras BASIK and Koheras BOOSTIK product pages.

Unique fiber delivery system 

Do you want to mount the laser system in a rack? No problem. With our unique fiber delivery system, aeroGUIDE POWER, you can get light wherever you want. The fiber delivery solution handles high power, preserves the low-noise laser properties, and delivers single-mode light at all wavelengths.  

This laser is robust enough for oil rigs yet sophisticated enough for the lab

Our fiber laser design is inherently compact and robust. It is developed for a lifetime of above 10 years in demanding environments where uptime is critical. With failure rates lower than 1%, we proudly deliver the most reliable low-noise lasers on the market. Alignment-free and maintenance-free.

The industrial-grade OEM lasers have a rugged design, a stable performance unaffected by changing environmental conditions, and wide temperature ranges in the field as well as the lab. We deliver lasers to the most advanced laboratories worldwide such as the Non-linear Quantum optics group at the University of Hamburg and DTU Fysik at the Technical University of Denmark.

We have more than 15,000 Koheras lasers deployed in the harshest environments on – and off – the planet. We have lasers on oil rigs, submarines, wind turbines, and even in space. With over 20 years of experience, we know they last. Also in your lab.

References

We are part of the European Quantum Flagship, the European Quantum Industry Consortium, the Quantum Economic Development Consortium, and the Danish Quantum Community.

Micro resonator-based frequency combs transfer the laser characteristics from the pump laser to its comb teeth. Any power fluctuations in the pump laser will be amplified in the nonlinear process that creates the comb.

Get the most stable frequency combs in the market with Koheras BASIK

The power stability and noise characteristics of the pump laser dictate the performance of the frequency comb. Lock your frequency comb to our Koheras BASIK fiber laser. They are mode-hop-free and combine low-noise with an ultra-stable all-fiber platform and a decade-long lifetime.

Have a quick look at the noise specification to see if the BASIK would work for you:

BASIKX15E15
Linewidth
[kHz]
< 0.1 < 0.1
Max. phase noise
[dB((Rad/√Hz)/m)]
-105 @1Hz
-125 @10Hz
-130 @100Hz
-128 @1kHz
-90 @10Hz
-110 @100Hz
-130 @20kHz
Max. phase noise
[(µrad/√Hz)/m]
3.1 @1Hz
0.6 @10Hz
0.3 @100Hz
0.4 @1kHz
32 @10Hz
3.2 @100Hz
0.3 @20kHz
RIN peak
[MHz]
Appr. 0.7Appr. 0.7
RIN level @ peak
[dBc/Hz]
 <-100 <-100
RIN level @ 10 MHz
[dBc/Hz]
<-135<-135

See all the Koheras BASIK X15 and E15 specifications on the product page.

Unique fiber delivery system 

Do you want to mount the laser system in a rack? No problem. With our unique fiber delivery system, aeroGUIDE POWER, you can get light wherever you want. The fiber delivery solution handles high power, preserves the low-noise laser properties, and delivers single-mode light at all wavelengths.  

This laser is robust enough for oil rigs yet sophisticated enough for the lab

Our fiber laser design is inherently compact and robust. It is developed for a lifetime of above 10 years in demanding environments where uptime is critical. With failure rates lower than 1%, we proudly deliver the most reliable low-noise lasers on the market. Alignment-free and maintenance-free.

The industrial-grade OEM lasers have a rugged design, a stable performance unaffected by changing environmental conditions, and wide temperature ranges in the field as well as the lab. We deliver lasers to the most advanced laboratories worldwide such as The Laboratory of Photonics and Quantum Measurements at EPFL and the Quantum Optics and Photonics lab at the Niels Bohr Institute.

We have more than 15,000 Koheras lasers deployed in the harshest environments on – and off – the planet. We have lasers on oil rigs, submarines, wind turbines, and even in space. With over 20 years of experience, we know they last. Also in your lab.

References

Our quantum engagements

Get stability and narrow linewidth with the Koheras BASIK X15

With the Koheras BASIK X15, you get a stable, ultra-narrow linewidth fiber laser with intrinsically low phase noise. Lock it to acetylene to get an even higher long-term stability. Optimized for 1542 nm, our BASIK X15 laser has become the preferred foundation for a rock-steady acetylene-locked laser.

On top, the BASIK X15 is mode-hop-free and gives you the narrowest linewidth on the market, just 0.1 kHz.

Phase noise specifications:

 BASIK X15
Max. phase noise-105 dB((Rad/√Hz)/m)@ 1 Hz
-125 dB((Rad/√Hz)/m)@ 10 Hz
-130 dB((Rad/√Hz)/m)@ 100 Hz
-128 dB((Rad/√Hz)/m)@ 1 kHz
Max. phase noise3.1 (µrad/√Hz)/m@ 1 Hz
0.6 (µrad/√Hz)/m @ 10 Hz
0.3 (µrad/√Hz)/m @ 100 Hz
0.4 (µrad/√Hz)/m @ 1 kHz

See all the Koheras BASIK X15 specifications on the product page.

Unique fiber delivery system 

Do you want to mount the laser system in a rack? No problem. With our unique fiber delivery system, aeroGUIDE POWER, you can get light wherever you want. The fiber delivery solution handles high power, preserves the low-noise laser properties, and delivers single-mode light at all wavelengths.  

This laser is robust enough for oil rigs yet sophisticated enough for the lab

Our fiber laser design is inherently compact and robust. It is developed for a lifetime of above 10 years in demanding environments where uptime is critical. With failure rates lower than 1%, we proudly deliver the most reliable low-noise lasers on the market. Alignment-free and maintenance-free.

The industrial-grade OEM lasers have a rugged design, a stable performance unaffected by changing environmental conditions, and wide temperature ranges in the field as well as the lab. We deliver lasers to the most advanced laboratories worldwide such as the Danish National Metrology Institute and the Quantum Optics and Photonics lab at the Niels Bohr Institute.

We have more than 15,000 Koheras lasers deployed in the harshest environments on – and off – the planet. We have lasers on oil rigs, submarines, wind turbines, and even in space. With over 20 years of experience, we know they last. Also in your lab.

References

We are part of the European Quantum Flagship, the European Quantum Industry Consortium, the Quantum Economic Development Consortium, and the Danish Quantum Community.