Can I receive a demo unit?

Yes! NIREOS is keen to provide demo units to users that would like to test our products.

Please contact us to schedule a technical call for discussing possible implementation of our devices in your setups, or to plan a demo at your facility!

How many Spectral Bands does it measure?

As HERA does not employ spectral filters or dispersive elements to direct the different colors of the incoming light to the different pixels of a sensor, it is not possible to determine the exact number of spectral bands. In fact, as the spectrum at each pixel of the image is the Fourier Transformation of the interference signal, the spectrum is a continuous function (or curve). Of course, when plotting the data, one needs to sample the spectrum with a proper number of points…but please note that does not affect the spectral resolution of the measurement and it is not an indication of the number of spectral bands!

The “real” answer to this question is that one needs to refer to the spectral resolution provided by the camera, rather than to the number of spectral bands.

Which is the illumination requirement?

Due to its extremely high sensitivity, HERA can work under low-light illumination conditions. This advantage is a consequence of the Fourier transform approach, as the employed interferometer (and the absence of the entrance slit) guarantees a much higher throughput compared to the dispersive- or grating-based technologies.

The camera is therefore very well suited in those applications in which intense and powerful illumination sources are not allowed, as they would damage the sample, such as in biology or cultural heritage. For example, HERA hyperspectral camera is so sensitive that it can measure hyperspectral images of the fluorescence signal emitted by a sample.

How does the Software work?

HERA comes with two software packages: one to acquire the hyperspectral images, see a preview of the measured data and save the measurement to your PC, and the other for a deeper data analysis. You can also export the hyperspectral data-cube in ENVI format.

As the hyperspectral data are heavy files, we strongly suggest to employ a computer with at least 16 Gb RAM and SSD drive.

How to calculate the Spatial Resolution?

HERA employs a 1.3 MP internal sensor and a 25 mm objective, providing 16° FOV. The working range varies from 25 cm to infinity. As an example, the lateral field of view of a scene at 1 m distance corresponds to: 2*tan(8°)*1 m = 28 cm.

Which is the typical Measurement Time?

HERA requires a few tens of seconds to capture the image of the scene and prepare the hyperspectral data-cube. Under low illumination conditions, acquisition time could be longer. During this time, the sample and the camera should remain static with respect to each other.

Also, the spectral resolution (which can be easily set via software) affects the measurement time: the better the spectral resolution, the longer the measurement time.

Is it possible to reduce the spectral bandwidth to decrease the measurement time?

No, due to the employed Fourier-transform approach, there is no trade off between the working spectral range and the measurement time. Therefore, you cannot save time by reducing the spectral bandwidth of interest. In fact, the measurement time is affected by the spectral resolution that you want to achieve, i.e. the better the spectral resolution, the longer the scan of the interferometer and thus the measurement time.

Can the GEMINI select a specific spectral band?

No, the GEMINI does not act as a monochromator, so it is not possible to select a single wavelength at the output, given a broad spectrum in the input.

The GEMINI Interferometer always transmits the entire spectrum of the incoming light, introducing a spectral modulation with a period that depends on the delay of the interferometer. For more information on the working principle of the device, please refer to this video.

Does the GEMINI work with coherent (i.e. lasers) or incoherent (i.e. lamps, fluorescent samples) light sources?

The GEMINI Interferometer can work in both cases, with the very same software and optical alignment.

Can I perform experiments with ultra-short laser pulses using the GEMINI?

If the GEMINI is placed “after the sample” (i.e. when the light has already interacted with the sample), then it is possible to use it with ultra-short laser pulses, as it does not affect the temporal resolution of your experiment. As an example, you can refer to this application in pump-probe spectroscopy.
Instead, if you need to use the interferometer “before the sample”, then the GEMINI-2D is the most suitable device. As an example, the GEMINI-2D is used in bidimensional electronic spectroscopy (2DES), in which it creates two replicas of ultra-short pump pulses with a precise control on the dispersion.