20-003906 Questions and Responses.pdf

NIMH-20-003906 Questions and Responses

Question #1

First, on page 1 of the Competitive Combine Synopsis, Description of requirements/Background paragraph 2 is:

“The Unit on Neuromodulation and Synaptic Integration (UNSI) seeks to purchase a FVMPE-RS multi-photon microscope system to perform in vivo imaging of neuronal activity with single cell resolution and receptor-based sensors in motivational circuits via the use of GRIN lenses and prisms.”

Response #1

The reference to a FVMPE-RS multi-photon microscope system is in error. The reference has been deleted in its entirety and replaced with the following:

The Section on Critical Brain Dynamics, NIMH (Senior investigator: Dietmar Plenz, PhD) requires a pulsed laser for their 2-photon imaging needs. The Plenz lab studies normal and pathological brain dynamics in awake behaving transgenic mice using laser technology. In short, the imaging laser excites fluorescent molecules that are being expressed in nerve cells of a mouse. This excitation allows for monitoring simultaneously the activity of thousands of neurons in the behaving animal. Using animal models for mental disease, the Plenz lab derives statistical features of normal and pathological brain function in order to identify mechanisms of mental diseases.

See Amendment 1 to the solicitation.

Question #2

Second, on page 2, Purpose is: “The purpose of this acquisition is to purchase a complete Chameleon Discovery NX System or “equal” complete broad wavelength range pulse-laser system. The purchase is required due to recent advances in laser technology and fluorescent molecule design. A modern laser for 2-photon imaging needs to cover a broad range of wavelengths to take advantage of modern fluorescence molecules/probes. Specifically, the lab needs to be able to excite probes in the short wavelength range of ~800 nm as well as long wavelength range of up to 1300 nm.”

Yet in the Purchase Description on page 6, point 2:

“Totally automated for hands free operation, the Chameleon Discovery NX delivers high peak power right to the sample plane using built in dispersion precompensation for the tunable output. The combination of short pulses (100fs at 900nm), high average power (>1400mW at 900nm) and widest tuning range (660-1320nm) gives brighter and deeper images for in-vivo imaging applications.”

With respect to “widest tuning range (660-1320 nm) noted in the Purpose section, the output is only needed from 800 nm to 1300 nm. Would the government consider amending this line to read tuning range of 680-1300 nm or more consistently, 800 nm to 1300 nm. This will increase competitive bid options and the change is extraneous to the science.

Response #2

The technical specification requiring a tuning range of 660-1320nm will not be amended.

Questions #3 and #4

Third and Fourth questions are with respect to point 3, same section:

“A second output at 1040nm, with high power (>3500mW) and short pulses (140fs) further enables multimodal capability for dual color excitation and activation of optogenetics probes.

The two outputs are phase locked, enabling techniques such as CARS, SRS and 2P wavelength mixing”

The pump lasers used in the Coherent Discovery and Spectra-Physics Insight products are different types of lasers, both very close in wavelength. The Spectra-Physics Insight uses a true solid-state laser at 1045 nm with transform-limited pulses of less than 200 fs.

The Discovery product uses a chirped output fiber laser at 1040 nm.

In terms of wavelength, we note that the spectral bandwidth of the Discovery fixed output is >13nm, FWHM which means the midpoint of the spectrum extends beyond 1045nm, making the 1045nm center wavelength specification functionally equivalent.

It is our position that the transform-limited 200 fs pulse out of the Insight X3 [typically 180 fs], is an optically cleaner pulse, when compared with the non-transform limited chirped fiber laser pulse of the Discovery 140 fs pulse and is better at the focus. For microscopes >5,000f2^2 @ 1040nm, which we suspect the user’s microscope will be, the Insight X3 delivers shorter pulses, even with the 200fs specification and 180fs typical. The excessive bandwidth of the competing fiber laser in the Discovery causes the pulse to broaden more through the microscope. The Insight X3 and X3+ will deliver shorter pulses at the sample.

Would the government consider revising the RFQ to read: thigh power (>3500mW) and short pulses (<200 fs) further enables multimodal capability.

Response to #3 and #4

The Government will not revise their solicitation.