The Unversity of Ottawa is pleased to invite qualified proponents to submit a proposal for a turn-key microscope and spectrometer system for measuring transmission, reflection, and time-resolved weak light emission from microstructures.
General Description of Instrument, System or Service
Suppliers to provide a turn-key microscope-spectrometer system for measuring transmission, reflection, and light emission from microstructures. The primary targetted application is caracterization of incoherent thermal light emission from surfaces that have typical dimensions on the order of a few micrometers (say 5 x 5 micrometers – 100 x 100 micrometers) and that are locally heated to temperatures in the 400-900 K range. Collected emission power on the order of a few nanowatts (1 – 100 nW) at mid-infrared wavelenghts (1000 – 10000 cm-1) is to be expected.
Due to the low light nature of the objects to be characterized, the proposed spectrometer should not be slit and/or grating based (e.g., a monochromator), but all-light should be sent to the photodetecetor(s) all time. This is commonly reffered to as the “Fellgett” and “Jacqinot” advantages,that is typically encoutered in Fourier Transfrom (FT)spectrometers. For simplicity, we therefore refer to FT spectrometer in the following. Spectrometers other than FT based and that would exploit the same advantages are unknown to the requesters, but are not necessarily ruled out.
The emitted light will be amplitude modulated (by a separate mean, not part of the requested instrument) in order to differentiate it from the thermal background. A lock-in amplifier for modulation and demodulation of the signal will be supplied by the requester and does not need to be included in the proposal. Ability to measure modulated signals is typically known as “Step-Scan” option in FT spectrometers, and is critical for the current application. Signal modulation in the 0-1000 Hz (minimun requirement) is to be expected, but systems that can resolve signals as high as 500,000 kHz or higher would be preferred. Ability to characterize modulated signals should require no special programmation or modificaion of the instrument by the requester, other than performing demodulation and supplying the demodulated signal to the spectrometer (see Fig 1 below)
Due the low light nature of the signal, it is expected that some detectors will be liquid nitrogen (LN) cooled. Helium cooled detectors should be avoided due to supply and cost issues of Helium. It is expected that the system will be capable of operating in the 10000 – 2000 cm-1 range with a detectivity D*>1.5×1011 cm Hz12 W-1 (typical of LN cooled InSb detectors) and in the 12000-600 cm-1 range with a detectivity D*>2×1010 cm Hz12 W-1 (typical of a Mid-Band LN cooled MCT detectors). At least one broadband room temperature infrared detector should also be included for enabling routine operation without LN (e.g. a DLaTGS detector). Beam splitter(s) compatible with the spectral ranges stated above should be included.
Suppliers are encouraged to present and itemize different detector options (other than InSb and MCT) that may offer comparable or slightly reduced performances, while increasing system flexibility. Possible detector alternatives include thermoelectric cooled InGaAs-based detectors.
It should be possible to collect the emitted light either through the provided microscope, or through an eventual optical setup that would sit on the same optical table as the spectrometer. In other words, FT spectrometer should have a side port for collicollimated light input (See Fig 1). Switching between the microscope and side ports should be straightforward for an average user and should not require specialized technical skills.
Although not the primary application targetted here, the system should be able to measure light emission from other mid-infrared emitters, such as mid-infrared lasers, in the same wavelenght range as stated above, either in constant wave, modulated, or pulsed intensity mode.
In addition to emission measurements, it should be possible to perform reflection and transmission measurement of the sample placed under the microscope. It is therefore expected that the system will be equipped with a radiation source. It is also expected that the microscope may need to be equiped with its own detector, in addition to those place in the FT spectrometer. Transmission measurements should also be possible within a sample compartment inside the spectrometer itself (i.e., the commonly encountered “sample compartment” of FT spectrometers).
Preference will be given to systems that are field upgradeable. In particular, the possibility to eventually upgrade the system on the field to perform measurement in the THz range by purchasing different sources, detectors, and beam splitters is desirable.
The system should come ready to go, with a computer and software installed. The software should not require a recurring license fee—i.e., a system that can becomes unusable due to software licenses expiring is not acceptable.
It should be possible to purge the spectrometer with nitrogen to reduce spurious abosrption.
Suppliers are asked to itemized the quote and provided costs for each item on the proposal.
Figure 1: Functional diagram of the requested system. Parts in red will be supplied by the requester and should not be part of the proposal. Blue indicates light propagation.
Specifications listed in Appendix A – Technical Specifications Compliance Form of this RFP are the mandatory minimum requirements for the Microscope-Coupled Spectrometer for time resolved thermal infrared light emission spectroscopy
