We evaluate the construction and performance of an ultra-low-cost full-field optical coherence tomography (FF-OCT) instrument, also known as an optical coherence microscope. Although the cost of construction of the instrument from off-the-shelf parts is at least ten times lower than those of commercial products, sub-4-micron axial and lateral resolutions are obtained, albeit at the cost of higher acquisition times. Standard test samples are imaged and the performance of the instrument is evaluated. The device is found to be useful in measuring length, dispersion and group refractive index as well. Suggestions for bettering performance are discussed.

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Expensive cameras meant for research applications are usually characterized by the manufacturers and detailed specifications [1] are available for them. Suppliers of inexpensive cameras usually do not provide such detailed information about their cameras. This data set provides the acquisition speed and noise characteristics acquired from a monochrome 1.2 megapixel CMOS camera, the QHY5L-II M [2]. The source code provided along with this data set [3] can also be used to acquire similar data for other QHY cameras. This enables the use of such cost-effective cameras for other scientific applications in other fields, beyond the designed use in Astronomy.

We report the first proof-of-principle demonstration of the resonant optical gyroscope with reflector that we have recently proposed. The device is very different from traditional optical gyroscopes since it uses the inherent coupling between the clockwise and counterclockwise propagating waves to sense the rotation. Our demonstration confirms our theoretical analysis and simulations. We also demonstrate a novel method of biasing the gyroscope using orthogonal polarization states. The simplicity of the structure and the readout method, the theoretically predicted high sensitivities (better than 0.001 deg/hr), and the possibility of further performance enhancement using a related laser based active device, all have immense potential for attracting fresh research and technological initiatives.

Instrument cost is one of the factors limiting the adoption of optical coherence tomography (OCT) from a wider range of applications. We present a couple of OCT devices using optical components which are commonly found in undergraduatelevel optics laboratories. These low-cost devices have lower signal-to-noise ratios (SNR) than top-of-the-line commercial offerings, yet can serve most of the needs of academic laboratories. A time-domain full-field (TD-FF-) OCT device has been assembled with Arduino control, which yields sub-4-μm axial and lateral resolutions. This device is useful where quick sample acquisition is not critical, but high resolution is paramount, for example with samples from material-science, or exvivo stabilized biological samples. Next, we discuss a spectral-domain (SD-) OCT device which delivers real-time video rate B-scans. This device is useful where real-time signal acquisition is desirable, for example with in-vivo biological samples. Cross-platform open-source software control for both these devices is also made available.